Combine consensual crime and warrantless searches and you have hubris.
If the DEA can’t obtain warrants for these phantom drug users, then they are essentially arguing if there’s a great number of drug users and suppliers that leave absolutely no trace of this activity. If they leave no trace, I don’t see why my rights must be limited in order to catch these people. If they are harming people, then get a warrant based on that!
Lucifer was not thrown from heaven for smoking a joint, drinking some beers, or looking at porn. These all could be considered to be vices, and taken to extremes they might all cause some form of harm. What got the devil kicked out of Heaven, though, was getting too big for his britches. Lucifer decided that he belonged on that throne, that he should be the one to judge men.