Ok, I know you should never post angry, but I'll run the risk in this case.
Because of the shortage of skilled .NET developers I often have to turn to contractors to get quality people in the door in the timeframe I need. In the past I've picked up some top notch quality people. People I am proud to have worked with (or am currently working with), who are integral parts of their teams, who work as much for the team as for themselves and who are genuinely missed when they go.
Then there's the bad eggs. You hear stories of those who misrepresent themselves in interviews, those who stop putting in after a few weeks elapse, or - like the one I had today - those who commit to a 6 month contract and resign 2 weeks into it because a job they've been holding out for was offered to them. Being used by someone as a short term cash source while they wait to see if the job they really want is offered to them is an unethical and dishonest way to behave, and hearing excuses about how they "don't normally do this sort of thing" doesn't make their behaviour any more palatable or acceptable.
I really value and appreciate the contractors I've met who are genuine and open about their situations. This other type of contractor just gives everyone else in the industry a bad name.