Apple means business this time — apps that sell sex are being tossed out of the App Store en masse.

For the past 12 hours, app developers have been getting notices from Apple saying that their apps have been taken down, due to a new policy that bans all "overtly sexual content".

Apple has a history of making sudden changes to its policies and removing apps, but a developer we spoke to said that the scale of the current purge is unprecedented.

One developer said he had had 17 apps removed so far, about half of its total portfolio. The latest notice came less than an hour ago, so the clean-up is still in full swing.

Developers were not warned of the new policy in advance, and it is unclear what prompted it. This could be a major financial setback to adult app companies, most of which are very small. But they don't anticipate going out of business. "It's not like pictures of beautiful women in bikinis suddenly became irrelevant," one developer told us.

Established brands aren't safe from the purge either. For the moment, Playboy's latest app is still up, but a number of Maxim apps have disappeared.

Apple has so far refused to confirm or deny a policy shift. The only statement from the company thus far states: "Whenever we receive customer complaints about objectionable content we review them. If we find these apps contain inappropriate material we remove them and request the developer make any necessary changes in order to be distributed by Apple."

Apple has not responded to a request for clarification.