That was possible a few years ago, when GPU's were what high end miners used. You could have a Javascript that harnessed the CPU's of your visitors for the duration of time that they were on your site.

Of course, Google noticed this theft of resources and (rightfully) marked those sites as being ridden with malware.

And to try to do it now? Even if you had Stackoverflows pageviews, I'm betting you'd end up with negligible income, and a lot of upset users.

Possible? yes. But if you were large enough for this to generate any significant hash power at all, someone would notice what you were doing, and wouldn't be worth soiling the reputation of your large-traffic site. You'd probably earn more in ad revenue per page load than you would maxing out their cpu for a few seconds.