An 18 year old lad from my village, who had just started a job programming, bought a drug from an online “pharmacy” and it turned out to be spiked with a synthetic opioid (N-pyrrolidino-etonitazene) and he died in his sleep at home, alone.
On your point about spiked products - it’s clearly a problem for online illegal drugs as well as those bought on the street.
The problem is, you don’t get to leave a bad review if you’re dead.