"DVD" Jon Lohansen has been tweaking Apple for years. After breaking the encryption on DVDs, he went on to unscramble Apple's music store files, then its wi-fi media streaming, then virtual locks within the iPhone. Now he's got his own company, doubleTwist, whose mission is to connect non-Apple devices to your iTunes library — the same sort of trick the Apple-baiters over at Palm recently tried and then apparently gave up on.

This ad, which inverts an iconic Macintosh ad by putting Jobs in the role of Big Brother, is sure to get plenty of publicity, just like the Apple store trick. Free press is, of course, far preferable to paid advertising. Any old hacker could figure that out; it takes a more clever one to actually pull it off.

The downtown San Francisco Apple store, at One Stockton Street, rents for somewhere around $2 million per year. Apple paid big bucks not only for the proximity to tony Union Square, with its upscale clothing shops, but also because the BART subway system has an exit literally underneath the building.

That valuable shopper-delivery spigot is what DVD Jon, real name Jon Lech Johansen, exploited: He simply rented billboard space at the top of BART's escalator, which sits behind the billboard in the attached picture, sandwiched between the advertisement and the side of the store. The placard touts his doubleTwist software, which allows non-Apple devices to be connected to your iTunes library (and which may or may not convert your Apple-encrypted files — the program is still in beta).

TechCrunch, which first published this shot, has another picture as well. The publication reports that "Apple employees are currently scratching their heads" over the ad; something tells us CEO Steve Jobs, now on medical leave, will take a more forceful approach with BART upon his all-but-confirmed return later this month.