not knowing if people are creating fake/double accounts to deceive you
everyone nowadays knows how to work with a vpn, the whole ip tool thing you got going on in your admin panel is freaking useless now basically and it's bothersome
not just that, people using a vpn constantly, kind of hard to ban someone perm from your forum
if you ban their account and a certain ip they use often, sure but the person can easily come back to do whatever using a vpn, correct?
I have successfully had a menace banned from his VPN for harassing one of our sites in the past. He was just a teenager, but he was doing some pretty damaging things as well as some thinly veiled threats against female members of staff. Believe it or not, it is a criminal offense and we could have pressed charges against him for a couple of offenses.
People think that they are safe doing whatever the fuck they want while using a VPN, but they're not. The world has moved on from the days were menaces could go around doing whatever and pulling down websites. If they're just spamming your site, you won't get far, but if they are doing criminal things to your site or online business, (OR threatening to visit your staff irl because they know where they live) you can do something about it. I spoke directly to the VPN company and they told me that while they couldn't give us personal info on the person, they would be holding his info for 6 months in the event that we take legal action.
I am a lot more tech savvy than I let on and I was able to find out this kid's real name and everything else through legal means. A friend who is an ethical hacker was helping me out too, but he also used very legal means. He backed off and promised to behave when we confronted him. He was quite shocked that someone like me would know a CEH hahah! He thought I knew nothing about tech. We didn't want to destroy a young kid's future career prospects, but hoped that he'd listen to my friend's advice and go white hat instead of black hat. XD.
My main point here is that you are never anonymous on the internet, unless you're a pretty skilled tech, so there are certain lines that they can't cross while hiding behind that VPN.
Someone coming back on new accounts is a mild issue. I'd just ban them each time. If they come back on a new account that you don't know about, and behave, everyone wins.