The US securities regulator’s lawsuits against crypto exchanges Binance and Coinbase this week marks its most aggressive legal assault on the digital asset market.

The Securities and Exchange Commission accused Binance and Coinbase, two of the industry’s biggest companies, of violating US securities laws, offering unregistered securities and operating as unregistered venues, among other charges. The duo account for half of global trading in digital assets.

Binance was also accused of mixing billions of dollars of customer cash with a separate trading firm owned by its chief executive and inflating its US platform’s trading volume.

The cases are the most high profile enforcement actions by the agency after repeated warnings from chair Gary Gensler that crypto exchanges and the tokens they were trading were likely falling foul of US federal laws.

After his appointment two years ago, Gensler frequently urged platforms to register with the agency and flagged that most digital tokens qualify as securities. His language hardened in recent months after the failure of the FTX crypto exchange last November.

After two big lawsuits in two days, the former Goldman Sachs banker-turned-regulator, who built a reputation in Washington for a hard-charging approach, was strident.

“We don’t need more digital currency,” Gensler told CNBC on Tuesday. “We already have digital currency. It’s called the US dollar. It’s called the euro or it’s called the yen, they’re all digital right now.”

Critics have bristled at the SEC’s approach, accusing the agency of failing to define the rules for their long-term policy for the crypto industry and instead regulating the market through enforcement actions.

“Regulation by enforcement is not an appropriate way to govern a market,” said Glenn Thompson, chair of the House of Representatives Committee on Agriculture at a hearing on the future of digital assets in Washington on Tuesday.

One of the crypto industry’s biggest complaints has been a perceived lack of clarity from the US regulator over what counts as a security. With the two lawsuits, the SEC laid out a list of more than a dozen coins it considers securities, including popular crypto tokens Solana, Cardano and Polygon.

By naming them, some lawyers think the agency has left the door open to target other crypto trading venues.

“These are complaints that strike to the very heart of the crypto exchange business model,” said Peter Fox, partner at law firm Scoolidge, Peters, Russotti & Fox. “They didn’t choose obscure digital assets that might only be on Binance to make their case, they chose well known, widely traded assets that are likely to be listed on many exchanges.”

But Gensler believes existing rules are sufficiently clear.

“I think there’s been clarity for years,” Gensler told CNBC, adding that investors are protected by securities laws and “crypto should be no different”.

Brian Armstrong, chief executive of Coinbase, said the SEC was relying on an “enforcement-only approach” that was “harming America” and that “the SEC and [Commodity Futures Trading Commission] have made conflicting statements, and don’t even agree on what is a security and what is a commodity”.

He added: “So if we need to avail ourselves of the courts to get clarity, so be it.”

Binance said the SEC’s actions “appear to be part of a rushed effort to claim jurisdictional ground from other regulators — and investors do not appear to be the SEC’s priority”.

Both exchanges have indicated they will fight the SEC’s charges in court. Coinbase has also said it will continue to lobby politicians to pass clearer rules for the crypto market in the US.

Gautam Chhugani, senior analyst of global digital assets at Bernstein, said: “The exchanges are going to dispute this and that dispute can only be resolved by Congress or the judiciary, whichever is earlier.”

But with lawmaking and enforcement cases likely to take years, some observers expect the regulators to file more cases in the meantime.

In recent months, US regulators have embarked on enforcement actions against crypto companies operating in the country including exchange Bittrex and Gemini, the crypto venue founded by the Winklevoss twins.

The SEC claimed Gemini and crypto lender Genesis ran a cryptoasset lending programme that was not registered as a securities offering, while the CFTC, the US derivatives regulator, in March sued Binance, accusing it and its chief executive Changpeng Zhao of operating illegally in the US.

“It is a very clear clampdown on the space and I don’t think the SEC is likely to stop here,” said Mark Palmer, analyst at Berenberg, about the Coinbase and Binance lawsuits. “I don’t know how any crypto exchange could think other than that it could be the next to be tapped.”

Crypto companies argue there is no easy path for them to register with the SEC, and that they find themselves in a precarious position. Gensler on Tuesday compared crypto venues unfavourably to traditional stock markets such as the New York Stock Exchange. The latter does not operate a hedge fund or make markets, he said.

He said: “If there’s real value in the crypto tokens, then compliance will build trust and the business model might change. It’s the hard work of earning the investing public’s trust.”

Fox, at law firm Scoolidge, said that even if crypto exchanges stripped down their services to resemble a traditional exchange “they would still have a massive problem because . . . you can only list classes of securities that are registered under the exchange act.”

“If the [crypto] exchanges registered as exchanges, they wouldn’t be allowed to conduct their business in any form remotely resembling what they do,” he said.

Additional reporting by Scott Chipolina in London

The Southern Poverty Law Center (SPLC) has listed the Republican-connected “parents’ rights” group Moms for Liberty as an “anti-government extremist” organization in its latest Year in Hate & Extremism report.

In a statement accompanying the report’s release, a spokesperson for the extremism watchdog group wrote that Moms for Liberty was the most prominent of 12 extremist “anti-student inclusion groups” mobilizing to “attack public education, ban books, and remove any curriculum that contains discussions of race, discrimination, and LGBTQ+ identities”.

The listing puts the group – whose members and endorsees now sit on school boards around the country – in the same category as anti-government organizations like the Oath Keepers, the Three Percenters and the John Birch Society.

In an emailed response to the Guardian’s request for comment, the Moms for Liberty founders Tina Descovich and Tiffany Justice wrote: “Name-calling parents who want to be a part of their child’s education as ‘hate groups’ or ‘bigoted’ just further exposes what this battle is all about: Who fundamentally gets to decide what is taught to our kids in school – parents or government employees?”

The pair added: “We believe that parental rights do not stop at the classroom door and no amount of hate from groups like this is going to stop that.”

Moms for Liberty was co-founded in January 2021 by Descovich and Justice – who had exited central Florida school boards after opposing Covid-19 restrictions at public schools – along with Bridget Ziegler, then in her second term on the Sarasota county school board.

The group soon expanded its campaigning remit to oppose teaching about racism and racist history and LGBTQ+-inclusive policies in public schools, and has since sought to land members and supporters on school board seats.

According to the SPLC report, the group has made its way by “intimidating and harassing teachers and school officials”, battling teachers’ unions, attacking corporations like Disney that are supportive of LGBTQ+ rights, and supporting and making use of laws like Florida’s so-called “don’t say gay” statute, which limits classroom discussion of gender and sexual identity.

Moms for Liberty has expanded into a nationwide network of more than 200 branches, and the SPLC now lists each of these branches as an extremist group.

While the group has claimed to be non-partisan, from the beginning it has had close ties to the Republican party, especially in Florida, where it has won the backing of the rightwing governor and 2024 presidential candidate Ron DeSantis.

Ziegler’s husband Christian was serving as vice-chairman of the Florida Republican party when she co-founded Moms for Liberty, and in 2021 he reportedly credited the group with getting “20- and 30-year-old females involved with the Republican party”.

In Florida’s 2022 elections, DeSantis made an unprecedented endorsement of a slate of school board candidates, many of whom were members of Moms for Liberty or other radical parents’ groups. In turn, Ziegler and other prominent members of the group offered vocal support for his rhetorical, legal and legislative attacks on diversity and inclusion measures in the state’s public institutions – or what the governor has called “the woke mind virus”.

Elsewhere in the report, the count of active extremist groups is at 1,225, which is not significantly greater than the 2021 count of 1,221. The SPLC attributed the slowed growth to a significant collapse in the militia movement, which accounted for only 61 groups in 2022, down from 92 in 2021, a fact the SPLC said was due to “members and leaders being held accountable for their role in the deadly Jan. 6 attack”.

However, in the statement accompanying the report, the SPLC warned that “hate groups are increasingly engaging in public demonstrations using flyering, marches and banner displays to gain media attention”, with schools in particular emerging as a target not just for radical parents’ groups, but for established hate groups like the Proud Boys.

In a statement, the SPLC president and CEO, Margaret Huang, called such attacks “a concerted effort by hate groups and extremist actors to terrorize communities and gain control of public institutions by any means necessary”.