Twitter is not a community. Twitter is a tool. A community can use Twitter, but I think describing spamming Twitter as destroying a community is disingenuous. The success of email, usenet and blogs/microblogs etc depend on their openness and easy access to all. Which also means people can and will spam them. So spam on twitter should be seen as a natural and nessecary side-effect, not the end of twitter. Berating the spammers will only increase your blood pressure - the spammers, tweeters and Twitter itself will continue as always.