You may be familiar with Playstation Plus Collection, a collection of PS4 games that can be played on PS5.
The case mainly concerns the market where access is sold to a PS5 owner who unlocks for you. It is these PS5 accounts that are permanently banned.
Fool all these games by lending the account, but beware
You get the collection if you have Playstation Plus. Although there are PS4 games, the games must be unlocked on a Playstation 5.
What players are doing now is sharing PSN accounts with PS5 owners so they can unlock this entire collection:
In other words: after unlocking on PS5, these can be played for free on PS4. The problem: if Sony finds out that you're sharing your account with others, they can ban your own, so be careful.
Sony with severe penalties: permanently bans the account
Of course, it's not very smart to share your account with others, but of course, if you know someone who is lucky enough to have a PS5, we see that it can be tempting, but Sony certainly follows the IP and you suddenly log on with a other IP range a number of times the account may be frozen.
Apparently, the person with PS5's account is locked permanently, while PS4 accounts are locked for two months.