Unfortunately, I've never found an in-depth discussion about the part about where they attempt to lure him to the United States so that he can be arrested. It always strikes me as a bit excessive.

That Valve worked with the FBI to get him sufficient permission to enter the US with the false pretense of getting a job seems to make this feel like much more personal than anything else.

And I'm left scratching my head as to what it really would have accomplished...