Yes, I think it's unethical. First, the data belongs to me, and I'm allowing a specific site to use it -- not you. Even for sites that claim they own my data,

Yes, I think it's unethical. First, the data belongs to me, and I'm allowing a specific site to use it -- not you. Even for sites that claim they own my data, it still doesn't give you any rights to it. Further, it is likely a violation of the ToS of a site if you're doing that.