I wonder how many people who are currently shielding Islam from the appropriate outrage it does and should invoke in people who value western culture... would be doing the same if an alien species from outer space showed up and said "oh hey guys, real sorry but our planet blew up and we're running out of fuel. Can we please live on Earth? Thanks! you guys are great!" but then we start to rapidly realize these aliens are eating human beings... not all of them, only about 80 or 90% of the aliens chomp a human being every now and then.
The 10 or 20% who don't eat humans are extremely apologetic for the others' behavior,
There's your problem. Alter the figures to >99% of the aliens who don't chomp human beings and it alters the list of possible reasonable/just solutions for dealing with the problem, if you want a more accurate analogy.
I personally would find it rather offensive if someone decided that British people are dangerous because of something that <1% of the population had done.
I also find it a bit odd that the religion of Islam has been around, shall we say, a fairly long time, and yet has only suddenly OMG ACTION STATIONS EVERYONE!!1! become "dangerous".
The other thing I find funny is that if I use your statistics in the most generous manner possible by switching them around to "10-20% of people who follow Islamic faiths are dangerous", and the number of people
estimated worldwide are Muslim, 15% of that is, oooh! ~230 million people are trying to kill me/Western society. I would never have guessed. To try and provide some perspective for that figure, a
conservative estimate for the number of deaths in WW2 is 62 million. I'm in the middle of a world war and I never even noticed.
So stop eating the crap that whatever media outlets are spoon-feeding you for their own profit (or governments for their own ends), and stop letting fear and sensationalist news dictate your thinking.