Some P2P software developers are bundling "parasite-ware" into their products that intercepts certain web transactions such as Amazon referals and diverts the referral fees to their own company to pay for software development according to this New York Times article.

Products include LimWire, Morpheus, Kazaa, and Bearshare. I use BearShare that uses the SaveNow program by WhenU which, I deleted from the Windows registry. To remove SaveNow and.doxdesk.com provides removal instructions.