Suggestion to counter RMT spams

I have received way too many RMT spams recently and it falls in the categories of harrasment and fraud crimes. So here I want to discuss ways to counter such spams. Of course, blacklisting them is the first reflex, but it does not work.

Here's the facts that I have gathered trought the short time I've been playing.

1. They use the search function in the settings, targeting specific groups, like those AFK.
2. They are probably bots since all they do is send spam.
3. The characters are deleted and then another one is created with a similar name (saw at least 4 variants of the same name spamming RMT).

So, using those three facts, how about limiting the number of characters that can be created per day? Limiting the creation of character to one per day would greatly limit their actions, but would also improve the performance of the servers.