*** WARNING ***
This will block large amounts of potential users in mass.
Your ownself has to judge their value.
READ THIS ENTIRE POST BEFORE DOING ANYTHING.
try it in smf
(not sure smf recognizes CIDR bans or not because I haven't yet been that far with smf)
Deny those IPs from your web site entirely.
go you your web hosting panel
look and open "IP DENY"
enter a CIDR in there
after page loads, click back
enter the next CIDR
those IP ranges then will not be able to even view you site directly, much less register.
Do that with each the IP CIDR's I posted
and I guarantee your dead end registrations will lessen SUBSTANICIALLY.
BUT THAT WILL BLOCK LARGE AMOUNTS OF ASIA and it's people
so really depends how much you value their usage.
Something interesting I have noticed....
I have a list of IPs sorted by country.
I removed the U.S. IPs and "dent from"d the rest
The more those I blocked,
the more comcast and rr IPs i seen being bad.
The more those i blocked, the more I seen from PSI and other california based Ips.
Also seeing more verizon IPs too
My point is...
alot of mischief comes from asia Ips
when you start blocking them, your trouble will lessen
but you got to remain watchful because of of them will start coming form other IPs and domains
and if you just automatically block those, you could block 1/2 your users.
You you always have to check the domain and IP whois info
and always watch where the largest number of your users are from
then block with care
Myself, i have standing IP blocks against a large number of world IPs
knocked a big hole in visitors
barely lessened the user interaction
and stopped 2/3 or more of all the negative stuff
watch for them to start using proxy connection via .de, .uk, nl, .it, ROMAIN AND POLAND
in smaller amounts .us & .ca
asia and russia are by far the bigger problems.
but you can never stop it all.