This is ironic, or ironico, as they say in Portuguese. Zynga is suing Brazilian social games developer Vostu for copying its games. Zynga, of course, has been accused and sued for copying games themselves (or Mafia Wars, which was inspired by Mob Wars) so if they are filing a lawsuit, the evidence must be over-whelming.Based on the reporting by Techcrunch, it's compelling. Screen shots of Vostu's MegaCity are quite carbon-copy like to Zynga's CityVille. Filing a lawsuit for copy infringement in the world of games, where "cloning" is an actual business strategy is a slippery slope.