People usually think "if someone spent the time and money to make business cards they must be legit" That's their weakness. I'm not a scammer or felon or anything like that, but from time to time I like my anonymity like at a party, bar, stakeout, or other situations you may not want to be known. I carry a fake business card printed on a type of paper that does not easily lift prints. I usually only touch the sides and on the face too just in case. When you get into a situation where someone refuses to let you go until they have proper contact info you can slip them a good old "John Doe Card" as I like to call them. This could save your life. I keep one with a fake home address (like as if I had a home office) on me. In actuality the address is usually a library or police station or something to that effect. I rarely circulate the same info more than 3 times. I was once in a situation where I was monitoring a Sexual Predator and Drug Dealer for the purpose of building a case against him. He demanded I prove that I was not a cop (which I wasn't, but I didn't want him to know really WHO I was). One business card was all it took. I usually don't approach the people I monitor but it's great when/if you get their attention. More than one time I had to get a throw-away phone and print it's number on a card so that the person could confirm the info was right. At about 15-20$ and no personal information tied to them throw away phones used to be worth it, but now I rarely use them.