When I ran a railway station we were constantly getting reports of abandoned bags. So guess who had to go and examine them!
The one which made me most nervous was a backpack with Arabic writing on it, and wires sticking out of it. (Fortunately, a PA message persuaded the middle-eastern owner to reclaim his bag, complete with the headphones for his MP3 player - which accounted for the wires sticking out!).
On another occasion I received a phone call from the travel agent who had an office at one of our unstaffed stations. He was very concerned about the fact that he'd just sold an airline ticket to Dublin (for travel later the same day) to an Irish guy who was in a very agitated state and carrying an exceptionally large and heavy suitcase. I was confident that there would be nothing to worry about but, to comply with the rules, I had to inform the British Transport Police. They also thought that it was fairly ridiculous but, again, to 'do things by the book', they had to apprehend him when he arrived at our station and ask him what was going on.
It turned out that guy had just had a massive row with his partner, packed his bag in a hurry and booked a flight back to his home city. Unfortunately, while the police were questioning him and searching his bag, he missed his connection to London, which probably did little to improve his mood!