How can i check if 2 members are the same person ?
Is there a way to see their IP or something ?
I dont like clones in my sites
You should find some WordPress plugin for that purpose. Users are general for whole website, they are not only wpForo users.
Do you know any that works with WPforo?
There is NO automatic way to do that, i mean check IPs against users. Also Wordpress doesn't log any IPs.
I use this plugin for logging the IPs to each user, for security purposes. Not for what you want to do.
Not sure how easy it is to compare manually all users IPs. Some users also have dynamic IPs.
Thank you Massimo i will have a look at it