CAPTCHA is an acronym which stands for "Completely Automated Public Turing test to tell Computers and Humans Apart"
I guess it tries to stop a bot from doing what a human can do on a computer. Usually we see it when we are asked to type in something on the computer screen from a goofy looking font that is staring at us. For loyaltyradio, it is when it says click here for the code and we manually type in what we are requested to type. If a person programmed a bot, it could get tons of points from PokerOwned if CAPTCHA was not used.