When I used to be a hoodlum, me and my "buddies" would need paint for our vandalism-related acts. We would go to Home Depot, and non-chalantly change the bar code stickers from, say, a brush, to a 5 gallon bucket of paint. We would also take advantage of special deals that were indicated by colored stickers or marks on products by bringing in a sharpie and making a mark on a given product. I guess it's a meme, not strictly a computer issue.