As an information security guy, i can tell you that posting a photo of your tag is significantly safer than registering for one of those discount cards at Walgreens. The databases that use your tag typically only track name, address, vehicle info, taxes, and some link an owner to a warrant database. Customer cards track name, address, credit card info, and shopping habits such as time of day you shop and everything you buy. The credit cards are bad enough, but you wouuld be amazed at what a person can learn from the rest of the shopping info. People are willing to give up a lot of personal info for a small discount. Sent from the voices in my head and transcribed by their drinking buddy.