As 'scummy' software categories go P2P packages are particularly bad, yup. Of course there are other similar problematic areas - web browsers, personal finance packages and anti-virus software are others that come to mind.

Time and time again it's been shown that the best (although by no-means sure) defence against finding unwelcome functionality(viruses, trojans or bugs) in software you buy is the open-source model. While you personally might not have the time or skill to read the source code of an application and search for them, the fact that it's published at least opens up the possibility that someone might. In fact in a world as large as the Internet, someone's bound to sooner or later.

This is why I and I'm sure others prefer firstly gnutella to other P2P schemes, and in particular LimeWire to some of its gnutella competitors. And yes, an open-source web-browser, personal finance package and anti-virus tool also