treborAre the "bad or nefarious people" teenagers? Adults?
This. Are they connected by a profession? Hobby? Interest?
Would not actually call that a hobby or interest, but it goes into that direction. Was the intent of the legislation to drive these people out of the area?
Yope. Explore. To create another area for these people, which had the effect of them leaving this one?
No.Is homelessness relevant?
No. Drug use?
Yes. Public drinking?
Not drinking. I'm hoping they weren't trying to drive out homeless people, but maybe did they enact legislation that allowed for more shelters?
No. Safe injection sites? A universal basic income, that helped people get back on their feet? Anything like these ideas?
No.This is reminding me of a puzzle I ran quite a while ago about learning the notes in the treble clef. The mnemonic the student came up with for the line notes was "Evil Gummy Bears Destroy France".
I remember it as well. That was a great puzzle. 
Is that puzzle relevant here?
Apart from the title, no. Is music relevant?
No.SarisberieI remember that puzzle! EGBDF. Good one.
Indeed.Were the playgrounds established to cover land which otherwise might be used for, say, more roads, or housing?
No. Were there trees which might be cut down otherwise?
No. Was the area a greenfield site originally?
Possibly. Or the land was used differently. Are allotments involved?
No. Bavarian language relevant?
No.The puzzle title is a reference to that song.
Herbert Grönemeyer: Kinder an die MachtThe lyrics roughly translate as:
Armies of gummy bears
Tanks of marzipan
You can eat up all the wars
Simple plan
Genius of a child
..
Give the power to the children
They don't care what they do
The world should be in the hands of children
End all gloom and dullness
Laugh away all problems
Power to the children