"Davi Barker, co-founder of the BitcoinNotBombs advocacy group, has recently described a run-in he had with the TSA. Barker was about to board his plane on his way back from the New Hampshire Liberty Forum, when he was stopped by two TSA agents. Barker, who was wearing a BitcoinNotBombs shirt and carrying a few hundred metal lapel pins some with the logo of Blockchain.info, a popular Bitcoin wallet and block explorer service was just cleared by airport security. But the TSA agents wanted to search his luggage again. They were looking for his Bitcoins:
I turned back to the orange shirt and asked 'What did the Bitcoin look like?' Bill chimed in and told the agent that what he was saying was impossible because Bitcoin is digital and doesn't have have any physical manifestation. You can't 'see' Bitcoin. The orange shirt said they looked like medallions or tokens. I said I didn't understand what he was talking about, and he simply repeated, in a child like way, that Bitcoins are like metal tokens. I told him that I didn't have any tokens.
The TSA agents suspected he was travelling internationally with over $10,000 worth of Bitcoins. This, presumably, might be seen as a form of money laundering. When another member of his group said that Barker was not going to fly out of the country, the agents simply turned around and disappeared."
In the 1970's. The original restriction was $10,000 US per traveling party if coming IN to the US. It's not illegal to do it, you just have to fill out an additional form once you declare it. Of course customs concentrates on the "and we get to confiscate it and keep it if you don't declare it and we catch you" part. IANAL so I can't cite the exact laws, but recently (in the past 15 years or so) the US also wants to know if you are LEAVING the US with more than $10,000 US per traveling party - this time under anti-money laundering, terrorism and drug trafficking laws. Most countries (at least here in Latin America) have adopted similar restrictions and penalties thanks to the US insisting that everyone else adopt certain US laws if they want to be allowed to trade with the US.
So long story short - $10,000 in the 1970's could buy you a luxury car or it was a hell of a slice of a house. Now you won't buy a car with it, much less a house. It barely covers the cost of a modest family vacation in Europe. But it's still $10,000 nonetheless and it won't change. Combine that with increasing restrictions on credit card use overseas (for your "security" of course, I'm sure you understand why we can't process that rental car/hotel payment), and traveling is becoming more of a pain in the ass every day.
And then there's the thugs who probably think that bitcoin looks like this [bloomberg.com] of course.