You can find Marc's write-up on the Symantec recycle bin rootkit here:http://www.sysinternals.com/blog/2006/01/rootkits-in-commercial-software.html
The idea is that the program catches files that hte operating system deletes but doesn't put into the recycle bin. If the user wants those files back, he or she can simply tell the program to put them back and it will do so. That's how the program is intended to function, by keeping deleted files invisible but still accessible by the user if said user desires. I don't have an issue with it, although he does make a good point reguarding how XP handled system restore VS. how Norton protected recycle bin handles it.