I have been a Kickass user for about 4yrs. Never had a virus, never had a problem. Looks to me like some of the reviewers above were just pissed that they could not use it to propogate their views. My experience is the moderators do not suffer trolls. Go figure.
Further to previous comment, Kickass have had a problem with people operating sites that look exactly like theirs. Make sure you are going to https://kat.cr/ These fakes will try to charge you money or direct you to another site where you have to log in and the ask for payments for the download. There is even a rather expensive VPN that has hijacked their name and pretends to be affiliated in some way. Just go to the correct address and the site works fine...