Dealing with multiple registrations from the same user

[Makoto]

This is particularly a problem when you run a forum using IP.Downloads with daily, weekly, or monthly download limits.

Someone can easily bypass any limits you have in place by registering for multiple accounts over and over again.

The only thing you can really do is monitor for this activity and ban users that you can catch. You'll also end up wanting to keep an active ban list for all disposable e-mail accounts you see people using. This all becomes a pain, and by the time you catch people in the act, there's already damage done. If you have download limits in place because you're bandwidth constrained, when a user can easily register 5, 10, or even more accounts in a single day in an attempt to rip everything he can off your entire site, it can be stressful trying to deal with. Not only this, but when you run a large forum that processes hundreds of registrations a day, it can quickly become a very time consuming daily routine.

I'm curious about adding functionality to try and deter this form of abuse. Some ideas I currently have,

1. An option to disallow multiple registrations from a single IP address in a set time period. The actual length of time that must pass before registration can occur again is debatable, it would probably best be left configurable by the admin, using hourly increments.
2. Use a method similar to COPPA registration. Basically, if a user attempts to register for your site and enters a birthdate bellow the age of 13, they can't just go back and reset their choice. While all a user has to do to avoid this restriction is clear their cookies, it's a functionality based off the assumption that most people won't realize this. Even the technically inclined could likely take it as a restriction based on their IP address and give up. (Or waste their time renewing their IP or attempting a proxy, but even then it's still a useful deterrent.)
3. Require admin approval for multiple registrations from a single IP and notify the user as to why their registration is pending.
4. Allow ban filters to be exported and imported. This would be useful for allowing people to keep an actively updated list of known disposable e-mail services in the marketplace.
5. Add a setting to allow IP.Downloads to restrict based on the members IP.Address, just as it does for guests. It would check both the members IP and account logs in this manner, making registering multiple accounts a useless effort.

[xbp-tpn]

You can use the following hook if you want

http://community.invisionpower.com/files/file/2847-duplicate-members-logger/

It will help you detect people who register multiple accounts from a single PC and let you set an appropriate action for such members.

[Makoto]

Thanks for that. I knew I came across that hook once before in the past, but never found it again.

The one you linked is an old version also, a new one was posted here,

I think I may definitely consider purchasing it.

(I also just realized I typed "IP.Address" in my above post, thinking IP.Board >_< )

[GadgetMan]

Too much money for this hook!!!!

[3DKiwi]

Too much money for this hook!!!!

Nonsense. One of the best mods I've paid for.

[Makoto]

Too much money for this hook!!!!

It's quite powerful and $25 is a reasonable price for all that it does.

I bought the hook months ago and I am still happily using it today.