Why do P2P file sharing protocol sites succeed?

Many other examples in queue

[Future]

Why do [peer-to-peer file sharing protocol sites] succeed, didn't any search engine was reported about the unethical activities about same ?
OR
It is yet another medium to promote my services ?

Its kinda gigantic business, though legally promoted !

I am aware about few site owners been sued few months back, but the site is still alive (STUPID LAWS).

[edited by: phranque at 11:14 pm (utc) on Oct. 12, 2009]
[edit reason] specifics [/edit]

[phranque]

there is nothing unethical about the technology nor the implementation of a file sharing protocol in a web application.

using such a platform for "sharing" someone else's property without permission is another matter entirely.