The San Francisco Daily, a free paper that began publishing May 3, already has some regular readers — at the FBI. Co-publisher Dave Price decided yesterday (May 23) to pull a joke classified ad offering plutonium for sale after the daily received a call from the FBI. The ad read: “Plutonium, weapons-grade. Must sell. Best offer. Permits needed,” and a phone number. FBI special agent Jake Millspaugh said his office had received “multiple” complaints about the ad, which has been appearing every day since the SF Daily began publishing on May 3. Price said he placed the ad to gauge the number of readers the new paper had — the more calls, the more readers. In the first few days after the SF Daily started, the ad only drew one call a day. But in the past two weeks, Price has been receiving three or four calls a day from curious readers. After telling callers that ad was a fake, Price would then ask them where they found the paper and what they thought about the new publication. The SF Daily also got a call from the California Department of Health Services, Radiologic Health Branch, which inquired about the ad. The FBI didn’t ask that the ad be pulled, but Price said he thought it was best to voluntarily stop running the ad given the unintended controversy it had created.