As spammers found a way to go through url links filtering and it seems they are creating new accounts in dozens i have disabled new accounts registration for now. Will try enabling in a few days. Or you may enable it earlier if you will find how to block them again and clean up the mess (LG? 
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UPD: changed the policy to Registration moderation.
UPD 2: disabled registration again as new registrations numbers are overwhelming and it is impossible to guess hwo is spammer or not.