Fair points, I'm in full agreement that we need to be cautious in taking action individuals simply because they are a member of a group. I can, however, identify groups that warrant additional scrutiny and skepticism. Members of the KKK, Irish Republican Army, street gangs, and former criminals for example. An ex-convict, is discriminated against due to his propensity to commit future crimes. While the individual ex-convict may be fully reformed; we as a society have determined that he is a member of a group that has a higher propensity to commit crimes. This requires former sex offenders to register, adds additional scrutiny for legal gun purchases, and even limits employment opportunities.

According to a February article in US News and World Report: Muslim extremists have caused 33/300 deaths due to terrorism in the US since 9/11.(3005/3305 if including 9/11) If looking at total terrorists attacks on us soil from 1972-2012 muslim extremists have committed 2.5% of all attacks. So, approximately 10% of deaths and 2.5% of attacks were committed by muslim extremists. Seems relatively low, until you consider that muslims represent only .8% of the entire US population.

At the same time, it is important to understand where muslim extremist hatred towards the west comes from. Americans and other western nations have been meddling in middle east affairs for hundreds of years. Since the discovery of oil, our involvement has been exacerbated. Our policy in the middle east needs to change, but that is a longer term project. Our immediate concern is protecting our homeland and helping countries like Jordan and Egypt to promote more secular government in the middle east.

In the wake of recent Paris terrorist attacks and Russian commercial airliner bombing, you might want to look more closely at the link between muslim extremism and terrorism. I'd start with the wikipedia page listing terrorist attacks in 2015. https://en.wikipedia.org/wiki/List_of_terrorist_incidents,_2015