Probably figuring your help would not be enough to stamp out spammers, Twitter is now blocking duplicate tweets. The logic is that someone constantly sending out the same message is likely a spammer. Preventing them from repeating the same message over and over again will make is slightly more difficult for spammers. It seems easy enough thought to make a program to rotate or add an irrelevant character, but every little bit helps.
"If you now attempt to tweet the same exact thing twice, Twitter will block you from doing so.
This move comes just days after Twitter moved to make it simpler for users to report spam users that were polluting Twitter. This move is in the same vein, spam users have long repeated the same tweet over and over again, often abusing hashtags to show up in searches for those tags, just to promote their links.
Of course, the move is not without complications. Given that TheNextWeb has a global readership, we might repeat a tweet to catch readers on different continents. Of course, it is simple to break Twitters move by merely altering a single character in the tweet. Doing so removes the block on that tweet, and releases it to the world."