I'm sure many can argue that this guy (or indeed anyone else) has a right to be a member of whatever organisation he wants, and I'll agree with that, but then he does not have a right to fly an aircraft and / or have whatever job he chooses.
Then make it a law: 'You are not allowed to be a pilot, if you are a member of a religious organization.' Good luck on figuring out the difference between a Sunday school religious organization and a fundamentalist one. On the other hand, in today's society 'whatever' organisation should be read as Muslim organization, since no one has beef with pilots being members of Arian brotherhood, Jerry Falwell's Liberty Christian Academy, KKK etc.
its also mind boggling how many people expect that they have a human 'right' to act in whatever manner they please regarldess of the effects to society at large.
I cannot agree with that. Look were we have come since 9.11. - you get stripped, searched about a dozen of times, liquids are of limits, if you had been to tanning saloon you will 'randomly' be picked at every single sec. checkpoint etc. People have been convinced that there is just a matter of days to another attack and if you will not comply with everything the Big Brother throws at you, well, you must have something to hide.
How can you have an effect on society if you or your friends are members of an organization?