As someone who came from a pretty authoritarian country- let me assure you that people there do routinely criticize their government, mock them all the time. Governments often do not have the bandwidth to deal with the volume of criticism, and even when they do- they wisely realize that letting people vent a little online is better than complete crackdown. I myself routinely did this in Facebook, where many in my friend list were government employees and (ex-ruling) party members.
I am in fact far more afraid of pro-palestine speech from USA as an immigrant than I was in my home country- and please trust me I am not exaggerating here.