According to an article on BBC News, Twitter is being sued by a company out of Texas on the grounds that it is infringing on three patents for a similar service.
The company is named TechRadium and their system, called Iris, much like Twitter, allows notifications to be sent to many users via multiple devices such as cellphones. TechRadium’s argument is that several would be Iris customers will choose to use the free Twitter service rather than paying for Iris.
The complaint from TechRadium states that Twitter intentionally and knowingly infringed on the patents and the federal lawsuit is claiming unspecified damages and a permenent injucntion against Twitter.

