https://techcrunch.com/2018/06/05/washington-sues-facebook-and-google-over-failure-to-disclose-political-ad-spending/

Facebook and Google were paid millions for political advertising purposes in Washington but failed for years to publish related information — such as the advertiser’s address — as required by state law, alleges a lawsuit by the state’s attorney general.

Washington law requires that “political campaign and lobbying contributions and expenditures be fully disclosed to the public and that secrecy is to be avoided.”