Cookie clearing is almost certainly not a legal issue; there'd have to be an explicit legal agreement between the setter and the keeper to be an issue in the fi

Cookie clearing is almost certainly not a legal issue; there'd have to be an explicit legal agreement between the setter and the keeper to be an issue in the first place. The "Referer" header is an interesting question. Hypothetically, if there's be some kind of renumeration for the site (eg: "I grant access to all of your users to my site and in exchange, for every referred visitor, you pay me 0.01 cent"), then spoofing the Referer would incur a financial cost to Google/Facebook. The incurred cost would be negligible for the individual user, but a case could be made against the extension publisher for the aggregated costs.