As a tangent to an interesting discussion at Dr. Jekyll & Mrs. Hyde's place concerning peer review conflicts of interests, Comrade PhysioProf raised the issue of chronic ass-sniffers:
People definitely will, if merited, gain the reputation of being an "ass sniffer" (so-called because they are always running around with their noses shoved up everyone else's asses stealing ideas) if they are perceived as scurrying around a subfield watching what everyone else is doing--at conferences, seminars, and via their access to unpublished information through peer review of grants and manuscripts--and always rushing in at the last minute with a contemporaneous "me too" manuscript that always seems to be less well-done, more superficial, and less comprehensive than those of the other lab groups.
Someone in one of the subfields we operate in is known for this. I was asked by an editor to review a very nice comprehensive manuscript in this subfield, and then after the review was completed and the authors were giving the opportunity to make major revisions and resubmit, the editor sent me a me-too manuscript that had just been submitted by our known ass-sniffer.
This paper was a grossly superficial poorly controlled rushed-out piece of me-too garbage, relative to the excellent manuscript that I had just reviewed. While you cannot accuse someone of literally copying the ideas of another lab without proof, I made it clear to the editor that the me-too manscript was not a useful additional contribution to the field. I think it is important for editors to do what they can to eliminate the incentive for ass-sniffing, and I think it is my duty as a reviewer to make clear the difference between work that originates an idea and develops convincing evidence for it, and me-too work that just rides its coattails. It is usually relatively easy to distinguish this kind of situation from a genuinely contemporaneous independent development of an idea, which is of course fine and should lead to simulataneous publication.