Google removed two Chrome extensions from the Chrome Store after they were recently bought by spammers. Spammers reconfigured the extensions to inject ads into websites visited by users. Google says extensions must have a single purpose and users should not be forced to agree to additional functionality. Purchasing extensions such as Add to Feedly provides spammers and adware purveyors with an effective vehicle to peddle ads for profit. Google pulled the extensions because they were in violation of the quality guidelines established by the company.
Source: https://threatpost.com/google-auto-update-weakness-exposed-by-ad-peddling-extensions/103750/