I came across an interesting post on twitter the other day (https://twitter.com/suffert/status/567486188383379456) that depicts a sidewalk with a sign indicating what wasn't allowed on the sidewalk. You have seen these before: NO bicycles, skateboards, rollerblades, roller skates, scooters. In the information technology sector, this is known as a black list; a list that defines what is NOT allowed or permitted. You can see black lists all over the place, input validation, output encoding, … [Read more...] about Black Lists and White Lists: Overview