A law that allows searches by law enforcement without reasonable cause is catching some Flathead residents by surprise.

The ACLU is calling it a "Constitution Free Zone" where law enforcement can search anyone without a warrant up to 100 miles from an international border or coastline.

What's allowed in that search?  It can be your car or even your phone and computer.

Anthony Johnstone is a law professor at the University of Montana. He tells NBC Montana that the "Constitution Free Zone" doesn't violate all constitutional laws, and that while it may upset some, the courts have upheld the law so far.

"In some instances related to immigration and national security, the courts have determined that certain warrantless searches near the border as far as 100 miles I guess in some instances are reasonable under the constitution," said Johnstone.

We wanted to know what people thought about the law, so we hit the streets to find out.

Some people we spoke with today say they're for the law, but declined to talk on camera.  Others don't see the need for it.

"What they're doing here is they're getting more power and giving less power to the people and we're getting the constitution set up to what it's supposed to be and they're trying to do everything they can and this is just an example of what's happening in the big picture,” said Libby resident Ora Miller. 

“I just don't feel like lawmakers should have kept this from us,” Kalispell resident Stephanie Strash told us.  “I myself just found out about it so I definitely don't think it makes any sense at all.”

“It's an invasion of privacy,” Logan Blades of Whitefish said.  “They shouldn't be allowed to do that.  I have nothing to hide but it's kind of your own personal stuff, you shouldn't have to show everybody."

A guide to the ACLU’s “Constitution Free Zone” can be found on their website.

A look at the Homeland Security’s take on the border searches can be found at their website.