I just came across this rather chilling interview Ed Yong did with scientific investigator Uri Simonsohn back in July.  Simonsohn has bee looking for evidence of fraud in social science research--and finding a really disturbing amount of it. "I don’t know how systemic the crime is." Simohnson told Yong.  "What’s systemic is the lack of defences. Social psychology -- and science in general -- doesn’t have sufficient mechanisms for preventing fraud. I doubt that fabrication is any worse in psychology than in other fields. But I’m worried by how easy it was for me to come across these people."  

Read the whole thing. Short version: there are a lot of studies that cannot be replicated, but they still pass as "science." Bushwah. Via Searching for Fraud - The Daily Beast.

Update: From the comments; disturbing if true:

I have a good friend that is a PHD in BioMed. He went through engineering with me and then stuck around to get a couple of masters in mechanical and chemical engineering before jumping into BioMed. His observation is that close to 80% of all medical studies are flawed, half due to poor statistical controls and half due to fraud. Several years ago he caught a new superstar PHD committing fraud by dramatically manipulating his results to fit the curve. Despite the overwhelming evidence the PHD was still offered tenure because his "results" brought in funding and publications.