Some oceanographer friends of mine were encouraged to apply for TWIC cards so that they could access research vessels in port without escorts. Because they're, y'know, researchers.
That's not how the TSA rolls, though, and they received nice letters on TSA letterhead explaining that "I have determined that you pose a security threat."
It's a good thing we found this out now, before the NSF, MIT, and WHOI agreed to pay tens of thousands of dollars a year for them to study here.
So let's review:
* Foreign students on F-1 visas are under no circumstances eligible for TWIC cards, even if they have a legitimate need to access US ports and research vessels.
* They shouldn't worry though, because anybody who has a TWIC card can still escort them (or anybody else) into "restricted" areas. Even though the TSA doesn't trust you, as long as someone they do trust trusts you, that's good enough.
* When the agency that's responsible for inspecting your shoes and liquids at the airport calls you a security threat, you shouldn't worry: it's not like there could possibly be far-reaching repercussions.
I feel better already.