WASHINGTON — The roiling debate over the U.S. government shutdown is extending to Twitter, Facebook and Instagram as fed-up Americans turn to social media to register their disgust with federal lawmakers for shutting down the government.

Those posting pulled no punches, calling members of Congress “immature,” “stupid” and “idiots” who need to “grow up.” There were a few attaboys, too, by self-described red-state conservatives who cheered on the Republican leadership’s unwavering stance against President Barack Obama’s health care plan, even if it meant suddenly pulling the paychecks of some 800,000 federal workers and threatening popular federal programs.

But mostly, tweeters said they couldn’t understand why a compromise between the two sides seemed so elusive.

“(hash)DearCongress, You should not be getting paid. In fact, you all should be fired!” tweeted Bruce Swedal, a 46-year-old Denver real estate agent who says he is worried about what the shutdown might do to home sales if federally backed loans dry up.

The public outcry playing out on social media sites this week is a new twist. During the last shutdown of government operations, in 1995, angry Americans would have had to look up their congressman’s address and sit down and write an old-fashioned letter or e-mail. But with the advent of Twitter, popular hashtags like (hash)governmentshutdown and the “Today” show’s (hash)DearCongress let voters log their complaints to all 532 members of Congress at once — provided they stay within the allotted 140 characters or less.