Chains Invent Insanity is a Cards Against Humanity answer card generator. As the name suggests, it generates cards based on a Markov Chain compiled from a wordlist. This wordlist is comprised of every single (official) answer card ever written for every edition of the game.
MPC is a company that prints custom decks of cards (54-234 cards per pack) in multiple sizes. You'll probably want to buy in bulk to get a decent price. People tend to use this service for their aftermarket Foo Against Humanity decks.
A site that lists every creditcard vendor and their Cardholder Verification Methods for the cards they issue. The site seems to be crowdsourced because the companies don't necessarily publish this stuff.