The Hill reports there was a coordinated attack aimed at taking down several pro-Sanders Facebook pages Monday night. Their weapon of choice: porn.

According to eyewitness reports, the pages were flooded with pornographic images in coordinated fashion and then flagged for obscene content, prompting Facebook to remove them.

“We had what looked like a kiddie porn posted in one of our groups today,” said Sanders supporter Erica Libenow, according to Heavy.com. “I reported that one. Seriously made me want to vomit.”

At least one Facebook user linked to the pro-Hillary Clinton group Bros 4 Hillary was reported to have participated in the attacks.

There are screenshots of one Bros 4 Hillary member who was also a fan of David Brock’s correct the record and a recent online initiative called Barrier Breakers 2016. This individual, who has since deleted his account, said online last night that he’d reported one of Bernie’s Facebook pages for making a “credible threat of violence.”

However, it’s not clear this person was representative of the group. A spokesperson for Bros 4 Hillary told Heavy, “Last night, a former member … decided to engage in harassing behavior toward Facebook groups of Bernie Sanders and posted about it in the B4H Facebook group…This was not promoted or supported by the leadership of B4H… We removed the offending posts and member as soon as possible.”

It’s worth noting that the reporting of a credible threat of violence is not the same thing as posting porn and then reporting the site. So the screenshots available online show similar behavior but don’t quite offer proof of a coordinated porn spam attack.

And there is one more wrinkle. Aidan King, the digital and social media manager for the Sanders campaign, claimed on Reddit that the Sanders pages went down as a result of a Facebook bug which affected many other pages as well. In other words, porn spamming and mass reporting had nothing to do with the pages going down. It was all just a coincidence.

So what do we actually know. At least one Hillary supporter connected to Bros 4 Hillary did create a false report against a Sanders Facebook page. People did see porn being posted on the pages. The pages did go down for about three hours from 9pm to midnight EDT. Someone on Sanders’ team says Facebook privately blamed the pages going down on a bug which impacted other sites as well. Facebook has not made a public statement about the problem so far.

Maybe the whole thing really is a big coincidence but the fact that it happened the night before a critical series of primaries makes a lot of Sanders’ supporters very suspicious. The hashtags #BernieBlackout and #BernieFacebookPurge are full of memes which assume this was a coordinated attack, one possibly connected with the $1 million Barrier Breakers 2016 initiative launched by David Brock.

To be clear, there is no evidence Brock’s group had anything to do with taking the Sanders’ pages down. Nevertheless, this version of events in which people connected to Hillary are trying to silence their opponents seems to be rallying Sanders’ supporters as they face what could be a tough day for their candidate.