Translation:You play with the users.
"Ich kämpfe für die Benutzer!" -- Tron
but this is after mit, so why it isn't " dem" instead of "den"
"dem Benutzer" is singular, "den Benutzern" is plural.
I had to go and read the about breakdown to really understand the cases. This chart may help if you are stuck http://german.about.com/library/blcase_sum.htm
Finally broke down and just memorized this chart http://de.wiktionary.org/wiki/das
vocally, how does one distinguish between dem and den?