Why was Facebook CEO Mark Zuckerberg hanging out with South Bend Mayor Pete Buttigieg and Elkhart firefighters?

Facebook CEO Mark Zuckerberg spent Saturday just hanging out in northern Indiana and, of course, posting his experience on social media.

Zuckerberg toured South Bend with Mayor Pete Buttigieg, posting two Facebook Live videos as they drove around the city chatting about the challenges of revitalizing the community.

Buttigieg (boot-edge-edge) explained that South Bend went from a muscular industrial city to one that plans to turn an old car factory into a tech center. The mayor spoke of community collaboration and smart sewers.

Zuckerberg's spokeswoman, told the South Bend Tribune, that the the Facebook chief knew Buttigieg previously and said they were friends.

Later, Zuckerberg posted photos of his ribs and chicken dinner with firefighters in Elkhart.

The visit, Zuckerberg said, was part of his personal challenge for 2017 to get out and meet people around the country.

Zuckerberg was in Ohio visiting with recovering addicts on Saturday morning. Sunday, Zuckerberg ate bratwurst and spent time with a family of dairy farmers in Wisconsin.

Tech site Mashable pops tongue into cheek to say that the Indiana visit is Zuckerberg's latest demonstration that he's not running for office.

Call IndyStar reporter Vic Ryckaert at (317) 444-2701. Follow him on Twitter: @vicryc.