The thing is, if a troll wants to use a proxy, there are constant numbers of new ones being created all the time, many that hide the fact that they are a proxy. It seems similar to outlawing guns to make sure criminals don’t have them.
OK. Please listen. I am not trying to teach you what to do as being so rude. Please don’t misunderstand me. I am just expressing my humble opinion, since I have some little experiences on how to deal with trolls and spammers.
There is something called dynamic IP. A troll just can reset his modem to get a new IP. That means he can always create a new account, no matter how much IPs you ban. Therefore I don’t see any reason to ban any IP, including VPN IPs. If someone is troll, just ban his account. The more you ban IPs, the more you prevent innocent people from viewing this forum. Because someone else can get the trolls’ IP through dynamic IP thing. Or, if you ban VPN’s IP addresses, you will unwillingly punish other people, just because they use VPN.
For me, the best method to combat trolls and spammers is to have as many moderators as you can have. They don’t have to be “mods”. They can be just trustworthy users who have the allowance in the forum script to nonpermanently suspend the accounts of spammers or new troll-like users. Suspension can be permanent in case the mods and admins agree. In the long run, you will win against the trolls since suspending an account is way faster than creating the new one. 
It’s not foolproof, but it’s reasonably effective.
We do. That’s always our method of first resort, but sometimes it’s not enough. The mods here have been banning spammers and trolls for a while and we’re fairly good at it. IP bans are definitely useful. Are you better able to access the board now that I’ve pared back one of the IP range bans you were asking about?
Ironic spam reported
Oh god, that is the funniest spambot post ever. Please please pleeeze keep it around (with a broken link) mods.
Harumph, fine. 
Crosses arms
For the curious, it was a spam post that copied text from some help site about how to get unbanned from a website.
Sometimes wishes come true.
Pony! I want a pony!
Don’t push it.
I promise I won’t push it! I’d love it and pet it and call it George.
Waow!!
spam reported
good luck.
Perhaps the best reply.
Spam reported.
The administrators of this forum have monitored your post real-time and deemed your post either
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- Of No Forum Material Value
- A Threat to Deemed Convention
- A Threat to Forum Legitimacy
- A Red Flag Within the Realm of Forum Paranoia
- A Random Hack to Which This Forum Had No Comment
- A Controlled Termination of your Membership Here and On All Other Associated Mediums
This is your second post in three years here at the Dope? 
I read the other one too. Um, interesting.
Sometimes in blocking undesirables (spammers) we also accidentally block legitimate users. That’s not our intent, we want the good people and want them to have access.
reported