In the distant past, I've been asked to show that my laptop works by turning it on (i.e. it isn't stuffed full of explosive) at an airport without a scanner, but I've never heard of anyone being asked to show what's on their laptop. As most laptops contain a few hundred thousand files (system...
Take a look at Wikipedia: Twitter - Wikipedia, the free encyclopedia Most of the article is waffle, but the first para, and the para headed 'Messages' might help.