Facebook Inc took down a popular Wall Street discussion group, Robinhood Stock Traders, in a move that its founder on Thursday described as backlash for conversations buoying shares of GameStop Corp and other companies this week.

GameStop, AMC Entertainment Holdings Inc and BlackBerry have been at the center of a market battle as individual investors coordinating on social media including Reddit, and using trading apps such as Robinhood, bought shares and squeezed hedge funds that had bet big on those struggling companies to tank.

Allen Tran, a 23-year-old from Chicago who created Robinhood Stock Traders, said he woke up on Wednesday to a notification that Facebook had disabled the 157,000-member group. The notification, seen by Reuters, said without detail that the group violated policies on “adult sexual exploitation.”

“We were first on the picking tree to be cut off because we are on Facebook, not a free platform like Reddit,” said Tran, referring to the typically lighter moderation on the discussion website.

Some of his group’s members made tens of thousands of dollars in recent trades first popularized on Reddit’s WallStreetBets forum, he said.

Tran, who also runs the 20,000-member HaiKhuu Trading group on chat app Discord, said he has never seen adult content on the Facebook group.

Facebook confirmed its removal but did not immediately have further comment.

Tran said institutional investors are trying to separate retail traders.

Facebook suspended his group on Jan. 7 after labeling it a “dangerous organization,” according to correspondence seen by Reuters, though the company reinstated its privileges after he appealed to contacts there.

“With all these major institutions being frustrated with the success of retail, they are trying to target any groups they can,” said Tran, who was featured in a Wall Street Journal article in November and described his Facebook group as the largest of its kind.

Tran expressed concern that a replacement group he formed to carry on discussions also will be taken down.