A German hacker,  Thomas Dullien who is known as Halvar Flakes, was denied entry to the US when the custom detected the training materials he’s bringing with for the Black Hat USA Conference.

The problem actually, according to the post of Mr. Dullien on his blog, was the way he enter US.

Had there been an agreement between my company and Blackhat, then my entry to the US would’ve been  “German-company-sends-guy-to-US-to-perform-services”, and everything would’ve been fine. The real problem is that the agreement was still between me as a person
and Blackhat.

Read more about it on his post and learn lessons from it.

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