It wouldn't be a hassle at all.
A hash table would be well suited for this. In the on open event you would do: hadd abusers $fulladdress $ctime (assuming you've already created the hash table called "abusers")
The $fulladdress serves as the hash table item which must be unique, the $ctime is the number of seconds elapsed since 1970. The good thing is you can format this value using $asctime to show it in your prefered <date> <time> combination.
Note I'm just using the $fulladdress as an example, you could use $site or their $nick or whatever will be unique and a means to identify them.
Doing a check on the hash table is easy with $hget, take a look in the help file at /help hash tables
Don't forget to open/load the table on start, and save the table on exit, or at a certain time interval using a timer.
I was going to give you the code, but I think you will greatly increase your scripting skill if you were to try to solve this yourself. The help file contains all you need to know.
