I see. I have a female friend in Vienna, she's said similar stuff to me. Things are getting bad there.
There are many valid criticisms of these kind of surveys, but crime, which is the hook that the anti-migrant posters like to use, is one of the criteria - so the idea that "It's getting bad there" is the one that needs rapid rebuttal.
They're already here. If you step back you can see how they've shifted discussion in a lot of threads with young or barely active accounts.
In the 2000s, Glasgow was known as one of the most violent cities in Europe. The average homicide rate from 2000 to 2002 was 62.9 per million people.[1] The homicide rate for San Francisco in 2014 was 45 per 100k people.[2]
Glasgow at its worst was comparable to Oklahoma or Indiana today.[3] Compared to Europe, the US just isn't safe.
(Homicide rates aren't a perfect metric, especially for comparisons over large periods of time, since social decline can be masked by medical advances. But they're good enough for back-of-the-envelope comparisons of similar areas.)
[1] https://www.gov.scot/Publications/2005/12/13133031/30384
[2] http://www.city-data.com/crime/crime-San-Francisco-Californi...
[3] https://en.wikipedia.org/wiki/List_of_U.S._states_by_homicid...