I haven't seen this reported elsewhere:

The executive order at https://covid19.ca.gov/img/N-33-20.pdf cites Government Law 8665 to enforce itself, which reads:

  CA Govt Code § 8665 (2017)  

  Any person who violates any of the provisions of this chapter or who refuses or willfully neglects to obey any lawful order or regulation promulgated or issued as provided in this chapter, shall be guilty of a misdemeanor and, upon conviction thereof, shall be punishable by a fine of not to exceed one thousand dollars ($1,000) or by imprisonment for not to exceed six months or by both such fine and imprisonment.

Six months of jail time and $1,000 is what they are threatening us with.