I agree with most of the comments that it seems like a spam tool and using twitter in domain name was not probably a good idea. However, I consider the approach that twitter took to be rather an extreme. They should have made an initial move by emailing the guy and asking him to shut down the service and provided reasons for it and given him a chance to change his practices. I just hate the fact that it is so easy to sue in US which IMO is also one of the reasons that insurance costs are so freakin high.