It is very legit. As was posted in Sweden they are starting to have many problems. Look up "sharia law london" and you'll see some areas with high concentrations they are trying to impose sharia law. (this happening before refugee crisis). There are news reports of ISIS defectors who returned and gave interviews to avoid punishment, etc. In Syria near Turkey border a report w/ pictures of shaved beards and how ISIS dressing as women to get in. Look up reports about the immigration camps, where they are forcing sharia law and the various refugees, shitties and sunni fighting, etc, and having to be kept separate. NO checks on the immigrants, so the smart ISIS who know their day is about over in Syria fleeing or returning.
Now what does that all mean? At the very least they have reports of violence and problems going on so most wanting guns may be just for protection from increased violence and problems and if any isis try to start causing chaos and random violence. I doubt any think they would be able to just suddenly rise and take over all of Europe since at least very few if any weapons will pass checkpoints and those jumping fences might get small arms in if any. But with so many there, a long term effect can be breeding and natural Europeans becoming minority or pressures and slowly bringing in sharia law as is happening in England.
AND non of the refugees are going to any other "Islamic" countries. It's funny they hate the Islamic countries, don't want to live in them, but then once going to a free country want to practice sharia law.