A photo purportedly displaying a gun warning below a "Welcome to Idaho" sign has been circulating on the Internet on blogs, message boards, and via email since at least 2013. While the "Welcome to Idaho" sign is real, the gun warning included with it is not.
There at least two photoshopped versions of the Idaho sign currently on the Internet. The first warns potential criminals that the majority of Idaho residents carry guns:
Attention Criminals & Terrorists
Over 170,000 Idaho residents have a permit to legally carry a concealed weapon, about 60% of the rest of the population is armed but have not bothered to purchase the license as it is not a requirement to carry a firearm. Understand, a substantial portion of the population is armed and prepared to defend themselves and others against acts of criminal violence.
YOU HAVE BEEN WARNED!
However, California, New York and Illinois have disarmed their citizens for your convenience.
The second photo simply provides a quote from fictitious Governor Nick Waite:
You may not like guns. That is your right. You may not believe in God. That is your choice. But if someone breaks int your home, the first two things you are going to do are... Call someone with a gun and Pray they get there in time.
Both of the photos are fake. The original photo was posted to Flickr by Francesco Dazzi on 11 August 2008. According to Dazzi, this "Welcome to Idaho" sign can be seen on the border between Wyoming and Idaho on WY Highway 22/ Idaho State Highway 33: