SAN FRANCISCO (CBS/AP) — An Oakland medical marijuana dispensary that’s been billed as the largest pot shop on the planet is being targeted for closure by federal prosecutors in Northern California.

Harborside Health Center spokeswoman Gaynell Rogers said U.S. Attorney Melinda Haag’s office has threatened to seize the property where the popular dispensary has operated since 2006 as well its sister shop in San Jose.

READ MORE: More South Bay Bars Demand Proof of Vaccination Despite Customer Backlash

Rogers said employees found the complaints taped to doors at the two locations on Monday.

READ MORE: Oakland A's Silent on Negotiations With City Over New Stadium

Although medical marijuana is legal in California, court papers filed Sunday said the dispensaries were violating federal law by selling marijuana.

The court action represents an escalation in a months-long, statewide crackdown on medical marijuana by Haag, who said last year she would try to shut dispensaries that were within 1,000 feet of schools, which Harborside isn’t.

MORE NEWS: COVID: Breakthrough Cases Surge Among San Francisco Hospital Staff

(Copyright 2012 by CBS San Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)