Union City is a city of approximately 70,000 residents, located on the eastern coast of the San Francisco Bay near Hayward and Fremont in Alameda County, California. Like its neighbors, the city has reported problems with prostitution in certain neighborhoods and within “adult-oriented businesses.” In April 2013, the Union City Police Department and Alameda County Vice Enforcement Team conducted a web sting to arrest both male sex buyers and prostituted women. Officers responded to listings soliciting sex on an undisclosed website, and arranged to meet the buyers and those they exploit at a local hotel. When an explicit offer or request for commercial sex was made, the individual was arrested. As a result, 14 men and women were arrested and charged with misdemeanor prostitution or solicitation. It is unclear how many of those arrested were sex buyers. When asked what inspired the operation, the Union City Police Department stated that it originally wished to identify and recover sexually exploited juveniles and arrest the pimps and buyers who exploit them. No minors were recovered in the sting, however.

In November 2017, Union City Police and the Alameda County Vice Enforcement Team conducted an undercover prostitution operation at a Union City hotel, resulting in the arrest of 15 male sex buyers.  The men responded to an online ad and allegedly agreed to pay money in exchange for a sex act with an undercover agent.  The Hayward Police Department, Piedmont Police Department and the Alameda County Probation Department were also involved in the operation.  The names and mug shots of the arrestees were released to news outlets.