As it relates to campaign spending: Money spent to communicate support or opposition of a candidate or ballot measure generally is considered an independent expenditure if the funds are spent in a way that is not coordinated with (1) a candidate or (2) a committee established to support or oppose a candidate or a ballot measure. For example, developing a television commercial urging voters to “vote for” a candidate is an independent expenditure if the commercial is made without coordination with the candidate’s campaign. Current law does not limit the amount of money individuals, groups, and businesses may spend on independent expenditures. These expenditures, however, must be disclosed to election officials.
source: CA Secretary of State