I am a white person who is asked several times a day to show ID. At the bank, to get prescription medication, the library, etc. At the school I work, I have ID fastened to my clothes and must display it all times. I get heat from administration for forgetting it. Before I fill up my car with gas, I have to go into the gas station to show driver's license before they will release the pump. Sometimes before I can use my debit card, I am asked for ID. For employment, I have always been asked to supply a Social Security Card before anyone would hire me.
At least once a month the cops in my community stop motorists in pull-overs for whatever whim the police department has that day. It might be a regular license check, or to see if your tags have expired or smell alcohol or pot in the car. You fork over your registration, insurance, and license each time and get fussed at, or fined, for not having all the paperwork. Cops hassle folks all day long; its part of the job we pay them to do. And just dare to go into a government building without identification...they won't let you in.
On the same note, each time I traveled to Europe, Mexico or Jamaica, I was constantly asked for my papers especially in hotels and trains/bus stations. My luggage was always shook down. All they want to know is one's purpose for being in their country and if the process you went through was legal or not. I understood and was glad to comply. It never occurred to me if I was being singled out or harassed for being a foreigner. It was simply a matter of complying with the host country's regulations, even if it meant whipping out those papers 20 times a day.