Perusing the bulletin board, there's a message about these four people who have been riding the buses. They get on at one terminal and take seats apart from each other. One takes pictures, another takes notes, maybe they trade around these duties, maybe not. They ride the entire route to the other end, and all get off.
Tourists? Maybe. Terrorists? Maybe. Some whackos just trying to get some attention? Maybe.
If we see this sort of activity, we are to alert the control center and file a security incident report.
So, knock it off, guys, the jig is up!