Last week I read an article about Twitter in the german magazine “Der Spiegel”. You can find the online Version here: http://wissen.spiegel.de/wissen/dokument/dokument.html?titel=Falsche+V%C3%B6gel&id=65243778&top=SPIEGEL&suchbegriff=falsche+v%C3%B6gel&quellen=&qcrubrik=artikel
The headline is: Falsche Vögel (in english: fake birds). It´s about the possibility that everyone can twitter in the name of a person who he isn´t for real. This could be especially a problem for celebrities and politicians.
The authors pick up the example of the german comedian Harald Schmidt. Another man used his name and tweeted a lot, e.g. bad gags. Magazines and Newspapers fall for this. I think this reflects how easy it is to manipulate people. You tweet and many people believe in it and rumour.
Another negative example: A few days ago they told in the TV that someone tweeted about the death of the critically ill US actor Patrick Swayze. He heard of his own death via internet, thats really macabre. Actually some Newspapers took this for serious and printed it.
The result is: Don´t believe twitter-news which don´t specify a (reliable) source.