Classic p2p services, like Limewire, are dangerous at best to use, as you're DLing DIRECTLY from another computer, and that computer could be anyones, from your neighbors all the way to Mark Ishikawa, the owner of BayTSP, one of the biggest anti-piracy Internet security firms in the world. The best "off the shelf" protection for those wanting to DL their fave stuff from free sources, such as PirateBay (side note here on TPB: They're not centrally located anymore and have multiple backups internationally, meaning they can't be brought down for any length of time. I recall the last legal attempt resulted in them being shut down for a total of a day and a half.) would be to use a true Torrent Program, such as Vuze (which is one of the most flexible torrent clients out there) or the actual BitTorrent client. Instead of DLing the full file from one source, which is easily traceable, you're DLing from multiple sources, and only a fragment of the whole file from every person offering the seed. Tracking through the torrent protocol is way more difficult than p2p, and, and the overall speed for DLs is way quicker
Bottom line? Limewire should have died years ago, but for some strange reason, it hung in there... I say let it die quietly. If people want to DL music and whatnot, they're going to and there's nothing to stop it from happening.