Re: Not IT, but a good laught for us…
Honest question: Is it immigration if you're only visiting temporarily for work? I thought immigration involved taking up residence in the destination? (But I may be wrong. As I said, honest question.)
Anyway, my real response is to share the story of a fellow student back when I was in college, who I'll Regomize as Phil. Like many of us at the time, Phil took occasional semesters off to get work experience in the industry. The industry, in particular, being computing, and his co-op assignments would take him far from our northeastern US campus to sunny Pasadena, CA, home of NASA's Jet Propulsion Laboratory (JPL). Clear across the country, but fortunately (as will become apparent) still domestic travel, so no customs or visas required.
What will also become apparent is that two things about Phil will be important to the rest of the story: First, although he is a US citizen born and raised in New York, Phil's family is from Jordan, and Phil himself is unmistakably Middle Eastern, ethnically. Second, Phil has a certain type of vision impairment (I don't know the name of the condition) that cannot be addressed with corrective lenses, where he can only perceive details if something is no more than a few inches away. To read printed text, for example, he holds the paper up in front of his face, so close his nose is literally touching it — it's the only way he can make out the words. (I don't believe he's legally blind, but his condition does prohibit him from operating motor vehicles, for one.)
All that established, let's look back into the past, to the mid-1990s. At the end of one 7-month co-op stint at JPL, Phil arrives at LAX airport for his flight back home to the east coast. At the security checkpoint, he sends his carry-on through the baggage scanner and walks through the metal detector. After clearing the portal without incident, he's pulled aside by airport security (the TSA didn't exist yet) who tell him they just need to perform a hand inspection of his bag and ask him a few questions.
This is where Phil's face droops, as he begins (somehow for the first time) to think about what exactly they're going to discover in his luggage. So, standing at the counter and leaning down like one of those drinking bird toys so he can see what's going on, Phil watches as an increasingly confounded security officer extracts the following items from his bag: A laptop computer. A travel alarm clock. An entire box of like 8 or 16 AA batteries. A telephone handset. (WHYYY?) An entire SPOOL of hookup wire. A folded map of greater Los Angeles. And a foil-wrapped brick of something that turned out to be some sort of homemade snack bars, and only LOOKED like plastic explosives in the context of everything else in the bag.
Fortunately Phil has the least threatening personality of anyone you've ever met, so the true explanation was also the most believable one: "Not a terrorist, officers, just a nerd." (And an idiot.) After some long and uncomfortable explanations, Phil was allowed to proceed to his flight. The security team probably got a good chuckle out of it, even. But as Phil himself has said, had this happened after 9/11 we would probably never have seen or heard from him again.