It seems like every year the run-up to Halloween is the same: Outrage about slutty costumes for women followed by fear about what is going to be slipped into your kid's Halloween bag. The only thing different this year is that the slutty costume is something related to ebola and the fear-mongering is about marijuana.
I live in Washington, where medical cannabis has been legal seemingly forever and recreational is more recently legal, so I possess a specialized knowledge set that includes such technical things as what that tricksy pot-infused candy everyone is suddenly scared of looks like. It looks like candy.
This is about the only thing most of the articles get right.
While I support your right to be concerned about the candy that strangers are giving your children, this particular fear is completely misplaced. It points to a basic misunderstanding about legal cannabis and the people who use it while portraying those people as vaguely threatening.