SexKey.com... Safe?

SexKey.com claims it's free.  Except you have to supply a credit card for "verification".  Any of you guys have experience with SexKey?  Are they safe?

On another note, how about HentaiKey GT?

I joined SexKey.com.  I had to give a credit card and I think I was kind of forced to take a trial of my choice from 2 porn paysites (not sure, was a while ago).  But as soon as I joined, I canceled the trial of the sites and I can still use my SexKey username and password.  I haven't seen any charges on the credit card I used so I'm pretty sure it's safe.