Version 7.5.8 add's in the "Stop Forum Spam
" detection modification that I wrote in 2013 and since then I've taken real world requests and monitoring spammers to see how they'll try to make it through; at this point I've expanded slightly and even the modification has been updated since it was first added.
First Release - Modification: Registration Detection
Second Release - Stock (now in 7.5.8)
Third Release - Registration IP Checking (vs just email; should now be stock) [Modification Link
Extension: (not in stock) Login Detection
Now, a lot of people just assume these are bots that are driving by spamming your sites; this isn't actually true, sure some are probably bots but a lot are actually humans, it's why they're so succuessful in skirting CAPTCHA systems, it's an actual human being paid pennies for spamming hundreds of sites.
I discovered a new tactic (well, new when it was discovered) whereby spammers would be "sleepers", this I'm assuming is in retaliation with how some sites are now dealing with spammers (by checking to see who they are when they register). Think of this, you have a fresh internet connection that is not in any database, go register a new email account and then go register on a ton of sites and then just jot down the access information; obviously you're not a spammer, you haven't spammed, but now you have a ton of logins to random sites.
So, now you go and hit all of those sites; sure, you're not listed yet, so you're golden, and you're already registered so it doesn't matter about registration checks...
Now; the Login Detection
addition to the Stop Forum Spam feature (well, modification but now it's "stock") checks a user against the database when they login, if they're a spammer they're not allowed to login, at least until they contact Stop Forum Spam to get themselves delisted (a legitimate user will generally do so).
Eventually I'd like to extend it to have a display of users who attempted to login who're listed as spammers, and reporting login attempts that fail to the SFS database.