Are radar detectors legal?

(As of September 2017, please check your local laws)

United States: 
Radar detectors are legal in the United States except for in Washington DC, Virigina and military bases. Illegal in all commercial vehicles over 10,000 pounds under US federal law.

Legal in British Columbia, Alberta, and Saskatchewan.

Other Countries & Territories: 
Please contact your local authorities.

Where do you suggest I mount my radar detector?