It's ironic that as an industry, and a nation for that matter, we asked the traveling public to be more observant and vigilent and report any suspicious behavior, and now that they do, we lash out with racism and stereotyping accusations. Had no action been taken, and something bad had gone down, everyone on this board would be saying "why weren't those people taken off the plane? Didn't anyone see how they were behaving before take-off?"
Suspicious behavior, in my opinion, is behavior that in and of itself may be harmless, but is out of place in a given context. Had these individuals used the airport's chapel or other private location to pray, there would be no problem. Many people simply aren't used to seeing people pray while waiting at the gate. Skimming magazines, listening to Ipods, playing video games, wrangling kids, looking bored, all of these are expected in the gate area.
As an airline employee, and a frequent traveler, I will take individual inconvenience over mass destruction any day of the week. It is sad that the actions of a few have such an impact on the many, but it is real.