Salesforce CEO Marc Benioff isn't happy about George Lucas' plan to open museum in San Francisco

Salesforce CEO Marc Benioff isn't happy about the prospects of filmmaker George Lucas opening his own museum in San Francisco - a plan that was rejected two years ago by the city.

In a series of tweets on Monday, Benioff voiced his opposition to San Francisco mayor Ed Lee's lobbying campaign to bring back the rights to build Lucas's museum to the city.

After failing to get the approval in San Francisco in 2014, Lucas has been working with Chicago city officials to build his own museum there, although the plan has recently hit a roadblock following a lawsuit.

But it looks like bringing the museum to San Francisco might also encounter some opposition.

"SF @sfgov & @mayoredlee should only support Lucas Museum if George Lucas does something for SF Schools, Hospitals, & Homeless," Benioff tweeted.

The tweets seem to raise concerns around the additional cost and tax breaks the city of San Francisco would accrue as a result of supporting Lucas' museum. According to the Wall Street Journal, Lucas's proposed museum in Chicago would cost $1.2 billion, of which Lucas pledged to pay roughly $700 million in total. The rest would have to be paid off by the city, which is one of the reasons why Lucas' museum still hasn't been approved for construction in Chicago. 

Salesforce declined to comment on this story.

Benioff's tweets against Lucas and Mayor Lee are the latest in the billionaire CEO's many acts of social activism. He's recently helped reverse a couple of "anti-gay" laws in the states of Georgia and Indiana by threatening to reduce investments in the regions. He's also known for rallying other CEOs to join his cause in order to win more public support, earning the nickname, "corporate bully," from certain lawmakers.

Here are the tweets Benioff sent out in response to Mayor Lee and Lucas: