About 20 minutes into their practice session, Dogen said two San Francisco Recreation and Parks Department rangers approached and asked whether he had a permit to teach tennis. “He’s my daddy,” his son told the rangers, Dogen said. 3 San Francisco dad Sam Dogen was questioned by park rangers for teaching his own kids tennis at a public court. The Recreation and Parks Department previously told The San Francisco Standard that rangers routinely check whether people providing instruction on public courts are operating commercially, since paid tennis instruction requires a permit. “Raising children in a city as expensive as San Francisco is hard enough,” Dogen told Fox News Digital.