Apple has filed a patent that forces users to interact with an ad. FTFA: "Its distinctive feature is a design that doesn’t simply invite a user to pay attention to an ad — it also compels attention. The technology can freeze the device until the user clicks a button or answers a test question to demonstrate that he or she has dutifully noticed the commercial message. Because this technology would be embedded in the innermost core of the device, the ads could appear on the screen at any time, no matter what one is doing.""
We've been following this story for awhile now but it seems to have broken into the mainstream.