Certainly took them long enough, but having been the latest service to be bombarded and misused by criminals, it seems at least one of the many heavily abused providers has seen sense and cancelled the option to create a free "domain" through them.
If you've been taking note, you'll have noticed the sheer volume of hostnames created on *.co.tv that have been involved in fake meds and exploits. Whilst co.tv were responsive, they certainly weren't quick enough to take down offending hostnames/accounts, nor were they at all pro-active (in order to prevent this in the first place). A quick example of those seen includes;
Lets hope .cz.cc, .co.cc and the likes, take note of co.tv's actions and do the same (personally I'd like to see the lot of them shut down, but that's just me).
Hat tip to my friend Mark for the heads up.