To be honest since we're such a very small community, it should be fairly easy to notice who the scummy cunts are - all we need is mututal respect, something that people like Beatdown have lack of. Mutual respect is pretty difficult to maintain large populations, but as I said since we're a small community, it should be pretty simple to offer your enemies some respect and not be that little cunt that multi-accounts or otherwise promotes an unhealthy wilderness.
Sure, people who can multi are technically doing somethat that is allowed, since the moderators allow it, but at the end of the day it promotes an unhealthy wilderness and a wilderness that's going to die sooner rather than later.
Approach 1
Remove Zenok, so little shits can't get to you on their alt to take back what you've taken from them - or just to multi you for that matter. Zenok isn't needed, it wasn't needed in 2002/2003 and it certainly isn't needed now. It's a shortcut, it's not a fundamental to the game mechanics.
Approach 2
Limit to 1IP. Not a great solution, but a solution none the less. It's safe to assume since the player base is so small, people who share the same IP will certainly be less than 1% of those affected - a necessary evil for sake of the majority.
Approach 3
Keep things the same and enforce bans or suspensions on those that multi. Sure, you'd need evidence, you'd also need man hours for moderators to review those reports via various means, perhaps logs and reviewing evidence. Basically, ban known people like Beatdown if they're caught multi'ing.
Approach 4
Do nothing and let the minority ruin it for the majority.
It's pretty simple, you need to take action before the minority kills your (our) server.