Yeah, as Nate stated, c_dilla is a licensing program. 3ds max and (I think) Inventor used it, so all of you guys who have those programs on your computer probably have c_dilla. Actually, I think I remember hearing something about Discreet investing a whole lot of money to use c_dilla across thier entire product line because it was advertised as very powerful piracy protection (for those interested, the crack was available on the internet less than a month later).
It resides in the C:\c_dilla folder (the folder is hidden by default.) If you delete it, though, you'll have to reinstall and reregister whatever program was using it for license management (and so, reinstall c_dilla).
I know some spyware checkers (in particular 'Spybot - S&D') pick this program up as spyware. I'm not sure why they do this - if you remove it, your programs won't work.
As for the TurboTax story, I do remember hearing a lot of controversy about the measures they took for piracy protections being too extreme, but I don't remember the details. If you want to know the details,
search Slashdot for all the information you'd ever want about it.