BOULDER, Colo. -- This is the time of year when college students start moving out for the summer, leaving behind an array of junk, or in some eyes, treasures, ranging from clothes, to lamps, to furniture. There's even an occasional computer left behind.

But police at CU Boulder have a warning before you "dive" into that Dumpster: do it, and face a fine of up to $1,000.

Police say it's no longer acceptable to rummage through someone else's trash. That's because there were so many Dumpster divers on campus last year, some students were actually afraid to go outside and throw stuff away.

Police also had a problem with non-students starting Dumpster fires.

So, campus police posted "No Trespassing" signs on trash bins warning dumpster divers to stay away.

At CU, students take spring cleaning to a new level.

"I've seen people throw out perfectly good futons, fridges," said CU senior Morgan Mauch.

But this year, those safety and liability issues have prompted a clear ban on rummaging.

"Every year we see a large number of unaffiliated individuals that come to campus with the intent to go through our Dumpsters," said CU police spokeswoman Molly Bosley. "This is really our attempt to ratchet up safety."

But many would argue one student's trash is a non-students treasure. And why would you ban anyone from reusing something that's still usable?

"If the university has such a problem with it, they should develop a program where students can donate such items and put them where they're actually needed," said CU senior Taylor Pianko.

The university said it does have a recycling program with drop-off stations in every building.

Still, some students say it should be expanded to perhaps even a year-end give-away.

"That would be a really good way to prevent Dumpster diving," said Mauch.

"There's a lot of potential for injury. There's a lot of items in there - sometimes we don't know what's in there. We've even had instances where people have thrown out hazardous materials and things of that nature," said Bosley.

The university said all temporary roll-in Dumpsters should be gone by the end of this week.

Those caught diving this week could face a maximum fine up to $1,000 and a maximum of one year in jail.

CU said its intent is not to fine people, but to have the option in case it's needed.

So far, Bosley said police haven't written any citations, so perhaps the additional signage is working.