Oh no! I'm really sorry to hear that!
Are there any security cameras near your storage unit? Maybe the bastid managed to get his or her mug on camera.
People can be so selfish, it makes my brain hurt.
Hang in there!

I am really sorry to hear this. As someone whose family has long had an off-site storage bin, two of my greater concerns include the potential for theft and/or erroneous seizure by the storage company.

While there is no immediate relief for the material loss/sense of violation that comes with this, can I make a couple of suggestions?

First, whenever possible, document what you have in storage. Make a list on your computer and back that up by documenting with photos. Second, if you have a homeowner's policy, check to see if that includes coverage for your off-site storage. (I know ours does; covers both our local storage as well as our daughter's during the summer while her dorm goods are in storage out of state.) That way you might be able to at least make a claim for financial reimbursement.

I apologize that I do not know whether or not storage coverage might be included with renter's insurance. If your residential policy does not include storage coverage, it can be purchased separately. Finally, and obviously, visit your storage space often to check on things, even if you're not stopping by to add or remove any items.

Fortunately, the locker is covered by my insurance, so I'm okay there. And that is some very good advice. I will definitely be visiting my locker more often, and hopefully just get rid of it outright and bring my stuff home.

Keep an eye for it on eBay. Maybe you will get lucky and they will try and sell it with an account listed in your area, although I am not sure if anything can be done if they do.

At the very least, I would request that the storage locker be changed so that the walls are secure all the way to the top and in such a way that the contents are not visible either from the hallway, the exterior or adjacent storage units. If they aren't willing to do those two things, find a better storage unit. Both are open invitations to future theft.