How can multiple registrations be prevented?

[Robert9]

Unfortunately, I have yet to receive an answer to this urgent question of mine. What happens when people register for the second, third, or fifteenth time?

Do they receive a message saying: "Hey, you already have an account here, it starts with 'Ab...' and the email address starts with 'ab...'."

Please use your old account and do not create a new one! We do not want that here! If you cannot access your old account or have significant reasons for creating another one, please contact us."

---

I've seen similar messages from other systems. How is it handled in XenForo? What happens, what can be configured, what might I have overlooked? Do we have any add-ons for this?

I'm not talking about spammers; they don't care about what I want or don't want anyway. I'm talking about the many people who no longer remember their old account details, have forgotten that they have an account, or those who want to bypass negative promotions.

I'm also not talking about detecting such multiple registrations, as there are several add-ons for that. I want the visitor to be informed that they already have an account, even at the risk of the system making a mistake due to the same IP, shared computers, or something similar.

There's only one reason I can think of why this might not be a good idea. A wife shouldn't find out through testing that her husband is active on a forum like "findyourlover.com". But maybe there are other reasons why this feature doesn't seem to exist? Or have I just overlooked it?

I am so tired of dealing with such cases every day, so tired of having to find out what’s going on. My client’s requirements are clear: No duplicate accounts without a reason. There’s no discussion on this.

What can I do to inform users of this right from the start, even as they attempt to create another account?

 

[Harpers Tate]

I suppose the difficulty is deciding what is a duplicate account and what is not. Two separate people might

• use the same IP
• use the same computer and browser
• have the same street address

and so on, and yet still be legitimately different; friends; husband and wife, etc.

Which is why it can never be fully automated, in my view. And why, therefore, the best we can do is attempt to detect and rerport these and make a human decision whether they are (as you suggest) old accounts forgotten, people with some nefarious motive, or genuinely different people.

And for those old accounts forgotten, is the reason that they have (for example) changed their EMail provider, not remembered to change their forum account, and can no longer receive confirmation messages and so on, and perhaps can't actually log on? In such circumstances, do you want to lose the member, or do you want to allow the new account (or fix the old one for them)? Again - best handled by human discretion.

 

[Suzanne O]

Speak to @Xon and get his sign up and abuse and standard library addons

 

[Robert9]

1. Excluding people might not be an option because you could accidentally block the wrong person.
2. Discussing the detection of duplicate registrations might not be something we want to do publicly, as it could give spammers and advertisers ideas on how to bypass it.

However, I still want the option to tell users: "Hey, you already have an account, so you won’t get a new one. If something isn’t working or you have special reasons, please contact us."

I’m pretty sure this will save me at least an hour per month. This one working day.

Along with many other optimizations I’m constantly working on, I’ll easily save one to two weeks per year, which I can then spend lying in the garden counting ants.

 

[ENF]

However, I still want the option to tell users: "Hey, you already have an account, so you won’t get a new one. If something isn’t working or you have special reasons, please contact us."

There is really no way to do this without some serious privacy issues. You would have to be getting into device fingerprinting or device ID's to get this level of tracking to put up this sort of notice and it still may not be accurate.