An anonymous reader writes "The Chicago Tribune is reporting that Facebook has sued a tiny start-up called Teachbook.com over the use of 'book' in its name. The start-up, which has two employees, aims to provide tools for teachers to manage their classrooms and share lesson plans and other resources. 'Effectively they're bombing a mosquito here, and we're not sure why they want to do that,' Teachbook.com co-director Greg Shrader told the Tribune. Facebook said its use of 'book' in its name is 'highly distinctive in the context of online communities and networking websites.' Facebook apparently is alleging that no other online 'network of people' can use the word 'book' in its name without violating its trademark."