Have you seen that all of a sudden you have followers on Twitter that you don't recognize? Twitter has gone the way of all of its email and web app predecessors and now is being attacked by both hackers, spammers, and all of those automated "bot" things that are seemingly always out trolling to suck up new email addresses, people, and content (do you ever wonder just who are the people that create such things and why they have nothing more constructive to do? i do--that is a whole branch of psychology that should be studied, in my opinion--a whole new area of deviance).
If you have experienced spam on Twitter, or if you have not yet but think that you could see this happening, rest assured--there are more tools coming out on the market to ensure that you are safe. One such service is called TrueTwit and positions itself as a "validation service" for Twitter. I'm currently trying it out, but I can see why it is quickly going to become a must have for organizations that wish to use Twitter and will require a new line item on the budget right alongside of virus protection services.