
Eric wants to get high, so he goes down to meet a dealer downtown and purchases some “illegal substances”.
He takes those substances back to his home, or a park, ally, bathroom etc, and consumes. In this circumstance, Eric hasn't involved anyone else unwillingly in what he is doing, unless he has invaded their private property perhaps, then he might be guilty of trespassing.
The trespassing that might have taken place though and his drug use are two separate actions.
The reason that many people today see drug use as violent is because drug addicts will often commit a myriad of crimes in order to fund their habit. Or those involved in the selling of drugs might engage in violence in the community as a result of conflicts with rivals etc. Those crimes that they are committing which involve the property of others are violent, yes but they should not be wrongfully conflated with the drug use itself. The actions are separate.
Stealing to fund the habit is wrong, trespassing is wrong etc, those actions are violent and involve victims. Drug use is not however, it's a personal choice and the only 'victim' is the individual user.
When drug dealers and those involved in the drug trade engage in violence, such as shootings or robberies etc, those actions are each separate and they shouldn't be combined as if they all constitute one action that can be labeled as 'drug use'.
It isn't civilized or just to initiate violence against someone for simply making a personal choice that others might not agree with. Whether that's consuming too many bad foods, drinking too often, not exercising enough, or consuming a controversial substance like cannabis. When we promote the idea that we should use violence to stop people from making certain choices then we are promoting the idea that we should violate their liberty and freedom. The choice is up to them to make for themselves, as an extension of their individual liberty, and anyone who tries to stop them from making it is the aggressor.

In 2017 there were more than 70k deaths attributed to drug overdoses in the U.S.
According to a recent United Nations report, professionals in the field of illegal narcotics are now calling for major reform when it comes to global drug policy.
Reform is badly needed, such as a rejection of the crusade against drugs entirely, as there have been thousands of people who have been cruelly murdered in the last decade alone because of their drug use.
While failing to prevent people from doing drugs or reducing supply any, the ongoing battle against illicit drugs has fueled a variety of negative consequences; contributed to countless human rights violations and threatened the health, safety, and security of many communities.
The war on drugs is accurately summed up to be 'immoral idiocy' as one media report has described. It's financed wars, filled countless jails with non-violent individuals, and corrupted politicians. It might feel good for some people to initiate violence against non-violent drug users but the approach doesn't work.
