I assume contact information

IMO that's a big one b/c it can dox sources.

Frankly I think most random internet activists won't be bothered at airports. But selected ones seen as "a problem" might be. They'd have to worry about their social graph. Who they communicate with, are ppl with similar views.

Also both journalists and activitists have to worry about fishing expeditions. "Give me six lines written by the most honest man in the world, and I will find enough in them to hang him." - Richelieu.