i am sure these both accounts (bf4 and bf3) are somehow linked to each other.
https://bf4db.com/player/929752758
and ..
http://battlelog.battlefield.com/bf4/en/user/noob-not-found/
https://www.pbbans.com/mbi-view-ban-294492.html
We don't ban for BF3 accounts.
even if it been used for hacking and accounts are linked ?We don't ban for BF3 accounts.
BF3 bans can be used as supporting evidence, but are never the core reason for a ban here.