Yep, they've been pretty persistent lately.
Most are long time members here so you might not know or remember but when signing up for an account here, Amand has put a couple of things in place that are specifically designed to try to keep bots/spam to a minimum. Firstly, when the new user initially tries to sign-up there is challenge-response authentication step in place that is primarily designed to curb bot attacks. Secondly, the user then can't post or sign-in until they reply to the initial e-mail that is sent (This is a standard internet account authentication step that is designed as much to protect the user as it is the site....).
Even with those standard protocols in place, of course scammers/fakers are still persisting and getting through.
Best advice I have is to try to ignore them as 'white noise' and know that the moderators are doing our best to delete the erroneous accounts as quickly as possible.
S.