The classic block game Tetris has frequently been the subject of legal disputes. The rights to the trademark are currently held by The Tetris Company, a corporation located in Hawaii that licenses the name to other parties. The Tetris Company, which routinely threatens legal action against clones of the popular game, has sent a DMCA takedown notice to Google, prompting the search giant to remove 35 Tetris-like games from the Android market.

Several of the games that were removed from the market were not actually using the trademarked Tetris name or any artwork from the original game—they merely had gameplay mechanics that resembled the Russian classic. In previous Tetris licensing enforcement efforts that have resulted in actual litigation, The Tetris Company has argued that clones infringe on the game's trade dress, which is protected under the Lanham Act.

Trade dress relates to the likeness of a product and aims to block the creation of knock-off products that bear sufficient similarity to be mistaken for the original. It's important to note that trade dress protections are not like design patents, because functional design elements are explicitly not covered.

Google isn't the first handset maker to make unauthorized versions of the block game disappear. Apple has also banned several Tetris clones from its own App Store. At this time, there appear to be several Tetris clones still available in the Android market, but it's unclear whether they will endure.

The removal of popular Tetris clones from the Android market is particularly frustrating for users, because the official Tetris game is awful. Developed by EA with a license from The Tetris Company, it is a poorly-executed port from the feature phone version and doesn't even fill the screen on my Nexus One.