Posted 06 September 2011 - 09:56 AM
As is so often the case, I don't think that P2P itself is the problem so much as what most people use P2P for. P2P is a great way for sharing large quantities of data among a group of people -- typically this means illegal copies of movies, etc. And the people who are interested is sharing property that doesn't belong to them are also, typically, the kind of people who might also pass along some malware -- either through malicious intent or just carelessness.
Linux, however, does have its roots in the academic world, where large quantities of data -- research results, publications, etc. -- legitimately need to be be shared by research teams, work groups, etc. Also, Linux distros themselves often get passed out in tgorrents. So, including P2P software is traditional and, in these applications in a defined community of trusted users and machines, it probably doesn't pose much risk.
On the other hand, I've never used it.