How do lichess find that we created multiple accounts?

Hey guys , do any one really know , how do they find people , who create multiple accounts on lichess.

If so pls say me.

They don't know until you don't message your other accounts . If you do, you leave blunders invisible to human. Visible to Computers

your IP and sandbagging.

Are you willing to create ?
So smart huh......
don't do that

@Pro1234Player not IP as I changes time to time may be Mac address

The internet you r using

It's related to fingerprinting the browser activity. Mac addresses, just like IP addresses can be changed from time to time, albeit by the user by randomization, so it's not used alone.