Demandprogress.org, an excellent political watchdog sent out a message about the MPAA's response to law makers now opposing SOPA or PIPA. You can contact your law makers here if you are so inclined.
The money quote is
Those who count on quote ‘Hollywood’ for support need to understand that this industry is watching very carefully who’s going to stand up for them when their job is at stake. Don’t ask me to write a check for you when you think your job is at risk and then don’t pay any attention to me when my job is at stake.The content industry didn't get their way, so now they are going to start turning the screws on law makers.