For a while now I've been hearing about (and thus keeping an eye on) stories from people whose laptops are being confiscated at the border and examined, as sort of a gill net for anything shady (or that they don't understand). Usually you hear about it in the context of people getting busted for carrying child pornography but more often than not it's Joe or Jane User. The US government says that going through someone's data without a warrant is no different from going through someone's suitcase without a warrant; Idisagree, for reasons better elucidated by Judge Dean Pregerson of the US District Court of LA than I: "Computer hard drives.. can include diaries, letters, medical information, financial records, trade secrets, attorney-client materials and information about reporters' "confidential sources and story leads." (quoted from the article, which quoted Judge Pregerson - click link for context).
Imagine it: Everything on your laptop can be copied and examined after the fact - your e-mails, your web browser's history, pictures of your kids, the book you're working on, notes from your last field assignment (I really doubt that the people who are going through all of this data while you're standing in line waiting would understand what a penetration test is, or the fact that they are often legally done)... they could potentially misrepresent anything on there in such a way that they could hassle you, bring you up on charges, or potentially whisk you away with a black sack over your head. The people in the field doing this aren't infosec professionals or lawyers, they are people trained to be paranoid, and to keep an eye open for anything that could potentially be illegal or dangerous (which usually amounts to things that they don't understand).
I don't know about you, but it worries the hell out of me.
EDIT: The following links will be of interest to people following this matter: