Last month, conservative sting video journalist James O’Keefe summoned reporters to a press conference at the National Press Conference in Washington where he promised to deliver a video that would expose “illegal activity conducted by high-level employees within Hillary Clinton’s presidential campaign.”

The video ended up showing an undercover operative working for O’Keefe’s Project Veritas purchasing a t-shirt on behalf of a Canadian citizen at a Clinton rally after campaign staffers first turned her down. Foreign nationals are not allowed to donate money to American campaigns, so the video purported to show Clinton staffers looking the other way as the rule was skirted to the tune of $40. The reporters in the room scoffed – one asked “Is this a joke?” – and moved on.

But now, the stunt could come back to bite O’Keefe, with a pro-Clinton group bringing legal action against the activist and his unnamed accomplice who purchased the t-shirt.

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Complaints by the American Democracy Legal Fund, a group founded by Clinton ally David Brock to weaponize the political ethics system against Republicans, usually seem aimed more at generating negative headlines than achieving actual legal outcomes. But the ADLF’s complaint against Project Veritas could be different, since O’Keefe himself acknowledged that his operative likely violated the law and captured the entire transaction on camera.

At the press conference, even O’Keefe’s lawyer, Benjamin Barr, admitted the video may have captured his client committing illegal activity, though he downplayed the severity. “It’s a technical violation of the law,” Barr said of the Project Vertias operative’s actions, comparing it to “campaign finance jaywalking.” “At most, it would be a small civil penalty,” he added.

But the ADLF alleges in a complaint sent to the Federal Elections Commission Wednesday that the violations are more serious. It accuses Project Veritas of breaking the law in three ways: That Project Veritas solicited donations from a foreign national, that its operative was a conduit for that foreign donation, and that the operative helped make a contribution in someone else’s name, which is prohibited.

“The illegal – and potentially criminal – stunt pulled by Project Veritas and its founder, James O’Keefe, backfired in a major way – unsurprising coming from the conservative activist who has previously been convicted for his outlandish and illegal recording practices,” said ADLF spokesperson Mary Jennings. ADLF’s complaint is also copied the Department of Justice’s Public Integrity Section, which would handle criminal prosecution.

It’s hardly the first time O’Keefe’s undercover stings have led to potential legal trouble. In 2010, he pleaded guilty to a misdemeanor and was sentenced to three years probation for another undercover video sting operation targeting then-Sen. Mary Landrieu.

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Naturally, O’Keefe’s group sees things differently. “We would like to thank David Brock’s group for publically acknowledging that senior Clinton campaign staff violated campaign finance law by willfully and knowingly accepting the donation from a foreign source,” said Project Veritas Action spokesperson Stephen Gordon. “As they allege that our undercover journalist violated FEC regulations, it stands to reason that the Clinton campaign is clearly guilty, as Project Veritas Action didn’t ultimately receive or benefit from the contribution while the Hillary for America committee did.”

Gordon also noted that two senior campaign officials happened to present in the booth conducting the sales when the incident occurred, raising the stakes.

Meanwhile, the anti-Clinton group Stop Hillary PAC has filed its own complaint with the FEC related to the video. In early September, it accused the Clinton campaign of violating the same three sections of the law that ADLF is accusing Project Veritas of violating. Stop Hillary PAC also requests an FEC investigation.