We are currently experiencing an abuse of our phone number verification service through the Kontalk main server - probably by a spammer.
The abuse started a couple of days ago from a single IP address. By putting more strict throttling rules and by blocking the IP we were able to counteract the attack.
However, starting yesterday, the abuser has adapted to change his/her IP address rapidly to workaround our throttling protection mechanism.
Unfortunately, until we find a more effective way to counteract this attack, I had to disable new registrations.
News will come soon through this post and social media accounts. Sorry for the inconvenience.