What are the disadvantages of Twitters?

Twitter says it has 140 million active users, with more joining every day -- but a small percentage of those are spammers. While Twitter has improved its security measures to detect bots and spammers before they become a problem, spam still exists on Twitter. Twitter enables users to flag what they deem to be spammers. Spam on Twitter usually tags your user name with a link to a website. It's easy to remove, but it's still a nuisance.

Twitter offers a direct message feature that lets users speak privately to each other, similar to sending an email or a message in Facebook. However, unlike those message-sending avenues, Twitter enables users to send direct messages to only one other user at a time. This makes its messaging system inefficient when compared with other social networking and communication means.