It appears likely that the manufacturers of guns are soon to enjoy legislated immunity from lawsuits. See here.
Should this happen it seems to me that Sharman has the perfect legal defense against the RIAA/MPAA. This would be bolstered by the Grokster ruling earlier this week.
If gun makers can't be held liable for criminal use of their product then I don't see how Sharman could be held liable for illegal use of the FastTrack network.
Plus, I don't ever recall reading about a death due to a driveby download.