Spammers/Hackers attempting to hack our user's accounts

[Infinite Guitar]

Hey folks,

We're having some spammer/hacker problems.

Please see attached image. It shows our "Who's Online" log. Within a span of a couple minutes there are multiple login attempts from multiple IP addresses all over the world. All of them attempt to login to random user accounts.

We've been getting many emails from our members saying that they've been receiving the email that says "Your account has been locked for 15 minutes because someone tried to enter with wrong password, etc."

This is extremely annoying for our members. We don't want our members getting these emails all the time just because spammers are trying to access their accounts.

It seems obvious that whoever is attacking is using proxy servers hence the many random IP addresses. Do any of you have advice for this type of problem? We can block these IP addresses all day but it probably won't do much since they're using proxy.

Any advice or help would be much appreciated. Thanks.