That sounds a bit disconcerting. I've discussed things like how to beat airport security, plant bombs to do the most damage, and in general ways to circumvent security measures. It's simply an intellectual curiosity, one even necessary to make things safe, and protect against those who think the same, but with intent of causing harm.
If the discussion alone is the damning part, with disregard to the intent... coupled with some prejudice, and add irrational fear.
Media may have used the term "discussed" but they were convicted for plotting. By legal definition, in order to commit a crime there has to be a proved conscious intent and actions taken. Even grouping together is considered an action, I assume for 16 years they've dome more than that. There was also existing home made bomb.
Sorry this guy is a criminal and a murderer, his value to society is pretty low to considering he hasn't done anything of a value in his life, except moving to UK.
If the discussion alone is the damning part, with disregard to the intent... coupled with some prejudice, and add irrational fear.
Self censorship is what you get.