Sorry, but I find the actions (if true) to be totally over the top. If you go down the road of refusing pax because of their nationality then you are opening a very unsavoury can of worms.
Would you refuse travel to Irish because of the IRA, Spanish because of ETA, Germans because of Bader Meinhof????
If there is a real risk to security then pax should be offloaded and dealt with accordingly. But to refuse carriage to someone because of their name is scare-mongering...