From many workers experiences i came to know that in Amazon Mechanical Turk there are several spam Requesters.These spam Requesters will reject your work or they will suspend. Be careful with these Requesters and earn money without any problem.
To know about any requester just install toolbar called Turkoption Toolbar developed by differenceengines. You can get this toolbar @ http://turkopticon.differenceengines.com/ . They have provide this toolbar for Mozilla Firefox and Google Chrome. Using this toolbar you can get all the details about the requester.
How Turkopticon works:
Turkopticon adds functionality to Amazon Mechanical Turk as you browse for HITs and review status of work you've done. As you browse HITs, Turkopticon places a button next to each requester and highlights requesters for whom there are reviews from other workers. Bad reviews let you avoid shady employers and good reviews help you find fair ones. You can view reports made against requesters with a quick click.
As you review HITs you've completed, are there HITs you weren't fairly paid for? Turkopticon adds a button that lets you review requesters from your "Status Detail" page.
Install it and earn money in safer way!!