I think that is to avoid fraud from tiping your self to much times. It’s a recomendation not to do this because your account and founds can be block. Any way thats a policy for publishers.
From nomal users like us, the only info that i know they use is our IP to avoid giving ads from another contry to someone using vpn. Any way for me is not quite a big deal, i mean Youtube and almost any page now uses that info for the same porpuses.