For me as a German it's frightening to see these protests.
It's not so easy to analyze this movement as it seems. Beside the obvious mix of nationalism and hatred against immigrants, the protesters also share a deep mistrust of the establishment, in particular politics and media.
Well, it's certainly not irrational to be wary of politicians and certain media. But it gets dangerous when you are so radical about your scepticism, that you distrust all of the established politics and media, and instead follow people and media which are far less credible and definitely have an agenda. In some parts of the German society, especially on the far left and far right, this issue is so profound that a lot of people with their entire peergroups are living in different realities. If a journalist from "Der Spiegel", ARD, ZDF, or any other credible German media, asks these people about their views, many of them react with insults or even refuse to say anything at all. But they don't have a problem to follow dubios 'journalists' who do nothing else then twisting the reality.
There are a few very popular, high influence, 'alternative' websites in Germany. Some of them are far right, but probably not in a way people outside of Germany would think of. No, they don't spread anti-semitsm! Actually they are on the side of the political hardliners in Israel. And they are full of hate against muslims and asylum seekers. With their views they are compatible to the so called "Neue Rechte" (New Right), a movement of the radical right that wants to distant itself to national socialism and the dumb "Neo Nazis".
The situation is potentially dangerous and it could lead to outbursts of violence. In the early 90s people died because of arson attacks. A few years ago, extremists killed at least ten people in the 'Bosphorus serial murders' (https://en.wikipedia.org/wiki/Bosphorus_serial_murders).
In the last days we have seen painted swastikas on a mosque and an arson attack on a house, destined for asylum seekers. Who want's this to be continued? I not.