it's the same as it's ever been...there have always been unethical growers that just want to make money, and don't care at all about quality, as long as it looks good enough to get people to buy it....the news is just paying more attention to weed now that it's become an industry.
the only thing you can do is get to know the people you buy from, ask them questions, if you don't like the answers, look elsewhere.....
i started growing my own for several reasons, and that was a major one....i use pyrethrin and spinosad,(both have low toxicity to human, and short half lives) in veg....once a plant starts to flower, it gets nothing sprayed on it outside of an occasional touch of calmag, and i'm careful not to get that on buds...