If you have a bike on campus, and this post is scaring you, get a better lock and learn how to use it. So many bikes I see around campus/town are secured with simple cable locks that you can cut with a decent pair of scissors.
Get a D-Lock with cable (example), lock up through your frame and rear wheel to a proper bike rack (not a street sign) and use the cable to secure your front wheel.
Not saying OP did anything wrong, I don't know how they parked it. But bike theft is a crime of opportunity, and I see a LOT of opportunities.
Hey, OP, your post could be more helpful if you'd give a little information about the circumstances.
As a cyclist who has invested thousands of dollars, I'd like some insight on how bicycle thieves are getting past common-sense methods to prevent theft or burglary.
Personally, my bicycles are in a locked garage except when I'm out on a bike ride.
If I have to leave my bicycle anywhere, I have a Kryptonite lock I use to secure it.
Generally, I never leave the bike anywhere other than locked in the back of my truck.
I see posts once in a while involving bikes stolen off porches or from behind a fence in a yard...
Just like leaving the keys in a running car while popping into a convenience store, if you leave your bicycle somewhere unsecured, with easy access, I don't have a lot of sympathy for you.
Use a Kyrptonite D-lock and you should be ok.
However, as others have said, don’t leave outside for long periods. It’s near impossible to steal the frame of a D-locked bike without using loud, powerful equipment. However, but other expensive parts such as brakes, chain set etc. can be easily removed with cheap tools.
Kids in some areas tend to vandalise bikes that have been locked in the same place for a while too.
That wasn't some cheap medium-grade lock.
And you don't seem to know how to use bolt cutters. With some thought and preparation, it's rather simple to cut off a u-lock in almost any position or situation. But please continue believing that your bike is secure...hopefully no one proves you wrong.
This is the lock I got for mine, very much recommend https://www.amazon.ca/dp/B06XCLTVPQ?ref=ppx_pop_mob_ap_share
Just get this set up and be done with it. I don't think a lot of people mess with this one too bad.