This has angered some German officials, who say the Dutch are hypocritical because they allow - and profit from - the sale of marijuana at "cannabis clubs."
Oliver was in the middle of his sophomore year at Oregon State University when he got involved in a cannabis club.
In California, the first state to legalize medical marijuana, a broadly worded law has allowed for the rapid proliferation of cannabis clubs and privately owned distribution centers.
Tom Cruise Purple is a strain of cannabis sold in California by select licensed cannabis clubs.
The Green Cross is a cannabis club, one of scores that sell marijuana to patients with a doctor's note.
In 2004, Oakland, the smaller, less glamorous city across the bay, banned many of its cannabis clubs, driving some to reopen in San Francisco.
For their part, tourists seemed unaware, and largely unbothered, that they might soon be wandering past a cannabis club.
The state's roughly 20 "cannabis clubs" will have to close, he said, based on a State Supreme Court decision on Wednesday.
Federal law continues to prohibit the distribution of marijuana at the cannabis clubs.
In more liberal areas, local health and police officials have worked with cannabis clubs, encouraging such controls as standard medical forms from doctors and photo identification cards for members.