Re: Some points to consider.
"They remove some of this propaganda material from the terrorist, but not everything, calming that some of it doesn't break their rules."
This just as it should be. If you want to say that ISIS represents the "pinnacle of human efforts to live as Allah demands we should" you're exercising freedom of speech. If you say "come join ISIS and help us kill infidels" you're recruiting for a terrorist organisation. Sure, sometimes it's a fine line and people will often get it wrong but making the effort is what democracies do and dictatorships have no interest in doing.