Video game piracy is not exactly rampant on modern consoles, certainly not to the extent that is on PC. However, even though the PlayStation 4 and Xbox One have largely been able to avoid piracy from becoming a problem, a whole bunch of ripped PS4 games have found their way to the web, including Grand Theft Auto V and Far Cry 4.
The good news for Sony is that unscrupulous gamers who want to grab a cracked game from the web and play it on their PS4 will have to jump through a hoops that will potentially deter a wider range of users. It starts with the PS4 firmware—as described in the NFO (information) files accompanying these games, the release group KOTF (Knights of the Fallen) says the PS4 needs to be running really old firmware. Specifically, version 1.76, which Sony released way back in August 2014.
That is the first big hoop, though not surprising—PS4s running v.1.76 were jailbroken in December 2015. The issue, however, is tracking down a PS4 that still has the old firmware. On top of that, the majority of games released in the past 2-3 years will not run on a PS4 that has not been updated. So, gamers looking to pirate an older game will not have access to newer titles (unless they have two PS4 consoles).
There is also the size of the files to consider. GTA V, for example, contains 90 files that are each 500MB. Far Cry 4 has 54 files of the same size, and Assassin's Creed IV, another cracked game, contains 84 files that are 250MB each. File sizes might be less of an issue than running a PS4 on old firmware—it is not possible to simply downgrade newer firmware to an older release—but it does count as another hoop.
Even with that in play, there will be gamers who go through the trouble of playing cracked games. How Sony responds probably depends on how big of an issue this turns out to be.