After he replied to her, he received this message:
hi again are you free right now totalk?
i screen so do this for me and message me on there
cant stay on much longer though
talk to ya soon,
The securedate link in the message points to http://www.clsafe.org/profiles/elizzy.
The sign up form is contained inside a frame. When you look at the source code for the frame you see that it comes from sexxxxmatch.com, a porn site.
Again, there is no CraigslistSafe verification service. Clsafe.org is not a dating site, it's just a scam used to sign you up for porn sites and the scammer who owns clsafe.org gets a commission for each person he signs up. Anytime a site asks to use your credit card to verify your identity, it's a scam like this one.