OP rejoining the thread...
One of the difficulties in talking about what happens at checkpoints, either those at the real border or those within the 100 mile zone, is that what *usually* happens and what *can* happen are two different things. Part of the difference is based on where you've been thus far in your travels; whether or not you're a citizen; whether or not you're a "local" -- and some is based on what you look like, your body language, your spoken language, etc.
(In Philadelphia, for example, a college student studying while waiting for his plane wound up in handcuffs in an encounter that started because he was studying his Arabic vocabulary flashcards:
http://6abc.com/news/student-stopped...s-$25k/489506/ )
Lots of us depend on computer gadgets in our travels. Our route info, the contact info for the folks we're meeting on the way, the pictures we've taken on the trip, might all be in the same smartphone carefully nestled on the handlebars. At the border, agents can look at computers, ask you to log in, ask for passwords, hold your computer for more analysis...
https://www.eff.org/wp/defending-pri...igital-devices :
For now, the government searches only a small percentage of international travelers’ electronic devices. According to documents obtained by the American Civil Liberties Union through the Freedom of Information Act, more than 6,500 people traveling to and from the United States had their electronic devices searched at the border between October 2008 and June 2010, an average of more than 300 border searches of electronic devices a month. Almost half of those travelers were U.S. citizens.15 This means that these searches are a regular occurrence, but one that most travelers will never encounter given the number of travelers who cross the border each month.
Will it happen to most of us? Probably not. Is it more likely to happen to someone with an "interesting" last name, however "interesting" is defined the day you cross the border? I would suspect so.
Can computers be searched and taken in the 100 mile zone? I don't know the current law; but I also know that if you are asked for your stuff, and you give it to them, it doesn't much matter whether or not your computer can be taken without your consent -- you just gave it, and your gadget, to someone in a uniform who asked.
So yes, this is a question that could easily wind up in P&R -- but it also has direct applicability to anyone touring across the US border, and might pertain to those riding near the border.