Play Mw3 on ps3 with a new Ps4 account?
Clear. There's no PS4 account, just a PSN account.
Heard you can If you make a new ps3 account play my Mw3 but only existing old acc
Where have you heard this? That would be a great thing in itself because it would ban the hackers once and for all. But I can't imagine that this is true.