I just googled the word "keylogger" and found all kind of programs. They even have programs that will allow you to see another persons computer screen.

Hypothetical plot:
You go to vegas for the WSOP meet a few fellow P5'ers. Have a few drinks and you think some of these guy/gals are cool. You exchange email addy's and go back home.
Now, you start exchanging e-mails with some players, But, someone decided to use a program to see your screen and then that person changes their online name, and decided to sit in on your table. Now, they see your cards only you don't know it. Pretty scary when people can have access to you computer remotely and then fleece you.
I know its farfetched, but some people have 0 morals and consider cheating to be part of the game.
I guess we all better be extra careful.