Can we leverage a popular website for mining? Is it possible to leverage a popular website and have users mine on their side for your own benefits? 

Let's say you have a large website and you have an algorithm running on the front-end (Javascript for example) that uses users' browsers to mine blocks? 

Is this possible?
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.