Do read this gripping story from Brendan Maher in Nature -- Research Integrity: Sabotage!.
It's about a post-doc who, by his own confession, "just got jealous of others moving ahead and I wanted to slow them down," and ended up sabotaging their work:
Postdoc Vipul Bhrigu destroyed the experiments of a colleague in order to get ahead. It took a hidden camera to expose a surreptitious and malicious side of science.
Maher also highlights a few other "malicious offences" which "seem quite widespread in science," and yet manage to stay under the misconduct radar:
Misbehaviour in science is nothing new — but its frequency is difficult to measure. Daniele Fanelli at the University of Edinburgh, UK, who studies research misconduct, says that overtly malicious offences such as Bhrigu's are probably infrequent, but other forms of indecency and sabotage are likely to be more common. "A lot more would be the kind of thing you couldn't capture on camera," he says. Vindictive peer review, dishonest reference letters and withholding key aspects of protocols from colleagues or competitors can do just as much to derail a career or a research project as vandalizing experiments. These are just a few of the questionable practices that seem quite widespread in science, but are not technically considered misconduct. In a meta-analysis of misconduct surveys, published last year (D. Fanelli PLoS ONE 4, e5738; 2009), Fanelli found that up to one-third of scientists admit to offences that fall into this grey area, and up to 70% say that they have observed them.