AILSA CHANG, HOST: All right. If you're not vaccinated and you want to grab a drink in San Francisco tonight, you could be out of luck. With the delta variant surging, hundreds of bar owners in the city have banded together to require patrons to show proof of vaccination or a negative test for COVID if they want to sit inside. Ben Bleiman is a bar owner and the president of the San Francisco Bar Owner Alliance. It represents more than 300 bars. He joins us now. Welcome. BEN BLEIMAN: Yeah. Thanks for having me. CHANG: Thanks for being with us. OK. So we've already been seeing something similar in Europe, right? Like, a number of countries there now require people to show what's called a health pass before they can go inside bars and restaurants. Obviously, this is not the norm here in the U.S. So what prompted all of you to do this?