I live in building 2030.  I don't know if it's someone living in this building, or workers coming in and out, but I think this could go for a lot of people on this base in general.  PLEASE HAVE RESPECT FOR OTHER PEOPLE'S THINGS!  We keep our 4 month old daughter's stroller in the downstairs area just like everyone else, but it seems we are constantly finding other people's trash inside her stroller.  We've found wrappers, dirty bunched up napkins and tissues, empty bottles, and even dirty wet rags have keep stuffed inside her cup holders.  Just yesterday I picked out a couple dirty napkins and found some sort of sticky nasty stuff dribbled across her tray.  It's really sad and unbelievable that people can be so rude, lazy, and disrespectful of other people's property.  This base is filled with garbage cans and dumpsters...my daughter's stroller is NOT one of them!  When we arrived here a little over a year ago, we were living in another building.  Even at that building someone was taking pieces of my son's wagon and cramming it into the door to prop it open.  Are you kidding me?!  I thought it was common sense that if something isn't yours, KEEP YOUR HANDS OFF!  And please please please...stop using strollers for garbage cans. 

I GET THE SAME THING!!!  I don't live in 2030, but I'm forever seeing things being stuffed in my stroller.  One time someone put a bag of chips on the bottom and it was emptied out of the bag and crushed.  I have a double stroller, what a pain it was trying to get them all out.  We've had toilet paper,  soda bottles,  and we've found GLASS in the seats of the stroller. My daughter sat down and got a pretty icky cut on her leg.  We found glass on the back seat, underneath in the basket, and on the tray in the front.  Ridiculous.  I don't know who it is, but I don't think it's the lady who cleans our hallways.  She carries a bag around for garbage.  She's seen me cleaning out my stroller and after  I explained to her what was happening, the next week I came down to find her cleaning the stroller out and making sure, as she explained,  "It was ok for baby".  I just think that people come down with their garbage bags, maybe something falls out or whatever and they don't bother to pick it up.    Other times they're just doing it to do it.  How hard is it to walk inside and throw it away, or out to the dumpster.  How immature can you be to put it in a STROLLER. I don't want my kiddos sitting in gross garbage.  Sorry for ranting, but after my daughter was cut on the glass I've been infuriated about the subject.  GROW UP PEOPLE!!!!

Sounds like something kids would do, middle school to high school age. Got any in your building? If so, then perhaps just mentioning that it's happening, but not accusing them, would be enough to get them to stop.