Why aren't official legal proceedings being taken against him to recover damages?

It's generally not worth it - going after someone in another country, paying the lawyers, etc. You'd spend more money than you'd get back. (Though every once in awhile, you run into someone who's more interested in setting an example than in money, and will jump through all the hoops and take it to court.)

That is one reason why the traditional punishment for thieves in Poserdom is ostracism. They usually are not punished in any other way. They don't have to give back their ill-gotten gains or go to jail. Instead, they're shunned.