[silveira]

The shapes are called tetrominos, four squares connected orthogonally. Tetris the game, was created with pentominoes (5 squares) and scaled down to tetrominos. The game was inspired by physical puzzles where fill a rectangle with the shapes. So these shapes existed before Tetris.

Would they go after the shapes? Possibly. See "Tetris Holding, LLC v. Xio Interactive, Inc.".

[rplnt]

One I remember is Blockles by OMGPop, which was a great multiplayer tetris-inspired game. There was legal threat, and they took it down in 2009.