The fact that Germany has seen such an increase in sales of Hitler's Mein Kampf is terribly alarming. The Trump campaign here in the United States has also been cited as giving a rise to white nationalism. All of this can, at least in my opinion, be contributed to the erosion of the middle class.
There has been a noticeable growth in hate crimes and attacks on minorities in Europe that signals a shift toward nationalism and extreme representatives like the neo-Nazi party that can have global implications. This increase is due in large part to the influx of Syrian refugees into Europe and is galvanizing a portion of the population that imposes liberalization of national borders. Nationalism was one of the main causes of World War I and Hitler's ideals expressed in Mein Kampf led to the genocide of the Jews in Europe, so there is cause for concern.
The rise of Noe-Nazis is a big concerned, more so after there was an overwhelming sales of Hitler's Mein Kampf. It is sad that people would think of embracing the ideologies of Hitler at this age. Nazism spread hate and led to the death of more than 2 million Jews, who knows what damage it can do now given the technological advancement in weaponry in this age.
This isn't a reason for concern. I myself read it just to inform myself as it's pretty interesting, the reason I did this is because I've always been interested in WWll as my grandfather fought against the Germans and I just wanted to know more about the reasons and how Hitler came to were he was. I would recommend people who love history/psychology to read it, maybe even make a course around it. The reason why I'm not concerned is that in my opinion there are two types of neonazi's: the first is too stupid to read so don't worry about them reading it, the second are the people who have a high iq, like Breivik, but I bet those people already read it before it was available in Germany again. A book doesn't make people bad, people can learn from it.