I can see this becoming popular rather quickly.
Edit: This won't affect retail keys; it's just a measure to combat trading/gifting cheaper games via Steam itself. Also, thus far it applies only to South America and Eastern Europe.
Edit edit: Having looked into the flag it seems it actually debuted about 15 hours ago, with the rather expensive Sonar X3 software, so I'm not surprised it flew under the radar until now.
Dark Souls 2 joins the list of shame.
Edit edit: The flag was re-added to Injustice's ROW sub:
Originally Posted by 34336 Injustice: Gods Among Us Ultimate Edition
The following games now have the restriction:
- South Park
And of course there's also Konami's own Lords of Shadow 2.