As you may know, when you're not registered on a forum, and you enter the "log in" page, there's a button. It says "Topic'it login."

What this button does is that when you have an account that matches within the e-mail you have on the forum and topic'it, it logs you in the forum with that account.
That's okay and in my opinion, is well thought out. The problem comes when you don't have any account in that forum, and you click that button by accident, or even worst, you already have an account on that forum with another e-mail, and it creates you another account

This has already happened to me twice because as I said, I'm used to using that button for four forums including this one, so when I'm in a forum with an account that uses a different e-mail, I get confused.
I was lucky enough to notice it, then report to each admin in each forum and the problem was solved quickly, but imagine you don't notice it. It can create a lot of confusion among the staff from that forum and the user itself, because, if you use the same nick, it duplicates it adding a "0" at the end.
So, I think it'd be useful to add a pop-up to ask for confirmation. It can contain something like "Please note if you don't own an account with (THIS_EMAIL) the app will create one with it. Otherwise, it will log you in". It's just an example. Of course, if you accept this suggestion it's up to you what to add: a pop-up, or anything else to avoid confusions.
Thanks for reading. If you have any doubt at reading this post (my English is not very good) or at understanding what I'm trying to say, please don't hesitate to ask

Have a nice day!
