We have pair of klepto cats here too. When they are on the comp table, they try to catch everything possible. Pens, papers etc. will do. When they get something in their mouth, they will take off from the table really fast and run somewhere with their treasure. Only to find that we're following them to take it away.

Here's a pic of them on the table, Casper is busy surfing though, but Kitty is planning what to take