Also, if he doesn't go through the formal visa process and tries to do his summer internship with a visitor visa, he may be banned from the US for 10 years. Given that he's publicly publicizing coming to the US to work, it would be very easy for USCIS to block his entry into the US.
I'd suggest checking this out: http://culturalvistas.org/
[0] http://travel.state.gov/content/visas/english/study-exchange...
But there are some pretty cool startups in Europe too, and given that Slovakia is part of Schengen he wouldn't have any problems with the visa if he were to work in Europe.
> But there are some pretty cool startups in Europe too, and given that Slovakia is part of Schengen he wouldn't have any problems with the visa if he were to work in Europe.
Schengen does not abolish visas across member states, as they had already been non-existent. Schengen removes border control. Visas and work permits are abolished as part of EU treaty.
I think that's not entirely true, as countries like Switzerland or Norway are not part of EU, so they have had visas which were abolished with Schengen.