Lemmy apparently hit with another bot wave tonight (+ 623686 overall users)
I looked at the lemmy stats again today like the last few days (since the 1st of July), apparently tonight there has been another wave of bot signups.:
Active last 30 days:
Lemmy: 59,438 (+ 2579)
Kbin: 55,532 (+ 433)
^ 2023-07-03 13:30:00 CEST
Of course "tonight" refers to tonight in central european summer time so it probably was more middle-of-the-day for you.
If you go to the site I linked at the beginning and sort by "Total users" you can see instances with 80000 users and 1 active user for example.
Open signups should be prohibited and affected instances should do something against the botted accounts or defederate. New instances should at the very least start using captchas and email verification.