Can you or anyone else also confirm that saves are also tied to the account that created them. I'm fairly sure they are but since this is not an area which concerns me I've kind of ignored it lol.
If you're playing a downloaded game, then yes, because you can only play the game when logged into the correct account.
If you're playing a physical game, you can continue playing on a different account, so the saves are accessible, but you won't earn trophies on the new account.
Not sure what happens when you switch back to the original account, whether the trophies 'catch up' with you.
eg:
- log in with US PSN account.
- play uncharted. Get trophies.
- log in with UK PSN account
- play uncharted. Warning 'you can't earn trophies'
- get 10 headshots (which would normally earn you a trophy). Nothing happens
- log in with US account
- play uncharted. Do some stuff. Do you get your '10 headshots' trophy or is it gone for good?