Active Shooter is a tactical FPS designed to simulate school shootings, which has unsurprisingly already been the subject of plenty of controversy. As of today, it can no longer be purchased via PayPal.

The Associated Press reports that PayPal has closed the account of publisher Acid Software, barring it from one of the most popular means of online payment.

"PayPal has a longstanding, well-defined and consistently enforced Acceptable Use Policy, and regardless of the individual or organization in question, we work to ensure that our services are not used to accept payments for activities that promote violence," PayPal said in a statement to AP.

Acid Software confirmed the closure on Twitter, adding hashtags "QuitCensoringUs," "FreedomOfExpression," and "WeWillBeBack." The studio has also removed the option to purchase Active Shooter on its own site, at least for now. However, a free demo is still available.

Active Shooter was previously banned from Steam, along with everything else by Acid Software and developer Revived Games, with Valve calling the man behind Acid, Ata Berdyev, "a troll, with a history of customer abuse, publishing copyrighted material, and user review manipulation." Active Shooter's Indiegogo campaign was also removed.

In a statement to AP, Bardyev said it "seems like everyone in US is trying to censor us, whilst not explaining what exactly we are violating." Acid's Twitter account indicates more information is forthcoming as the publisher figures out how to continue selling its games.

You can read the details of PayPal's Acceptable Use policy here.