SAN FRANCISCO—The Haight-Ashbury district was all about peace and love until bacon entered the picture.

The trouble began in May, when this city's health department shut down a popular restaurant called Bacon Bacon after neighbors' complaints caused a permit delay. The neighbors' concern: the scent of bacon grease was blowin' in the wind.

Now bacon lovers have found out, and they're raising a stink.

Ahead of a permit hearing scheduled for Thursday, nearly 3,000 bacon advocates have signed a petition in support of Bacon Bacon. Phylis Johnson-Silk, who lives around the corner and loves the place, is making signs that say, "Bacon rules!" and "Really? You complained to the cops that you smelled bacon?"

The restaurant's owner printed up shirts that read, "Smell this!" and says they are selling like hot cakes. Bacon Bacon devotee Nick Barnes, a 24-year-old who tattooed the shop's logo on his wrist a year ago, says he is "devastated" and has posted on his Facebook page about the restaurant's closure.