I have a bumper sticker on my vehicle that says
Polite as Fuck
The sticker is about 3" × 5" (7.6 cm × 12.7 cm) in white block lettering.
My employer has told me to remove the sticker or face disciplinary action. They also said there have been two complaints received within the year. The car is a personal vehicle and is not used for any type of company business. The vehicle is parked on company property (their parking lot that all employees use).
I live and work in the United States. Would this be considered a freedom-of-speech issue or does the company have the right to ask/tell me to remove the sticker?
Update: Regarding some of the answers and comments; I was not intending to walk away from my job over a bumper sticker. The sticker can be bought here and has a large following here and has a community known as "a drinking organization with a charity problem".
A better question might have been related to professionalism of the sticker and if it was such a big issue that my employer needed to be worried about it?