Strange Guy.... Stalker maybe?!?!?!

Am
I'm trying to figure out what this guys issue is. So hubby and I went to the library a day ago. The security guard inside the library kept following me around. All i had was my wallet and that was it. I used the computer(he walked by 6 times) to print something off. After that I was finished. Then to make matters worse he followed my husband and I outside while we got into our car. Once we got in our car, he left. But I'm trying not to make it obvious but I'm talking out the side of my mouth in the car to hubby, "He's been following me ever since I walked in..." I was just flipped out by that. Just ugh! Has this happened to you before? What did you do?