wvproxy.com weirdness

So – what is wvproxy.com? it is proxy site of a company called web visible.

What do they change?

I did a wget of a website and then the website with .wvproxy.com appended and then a recursive diff against those two resulting folders. The changes I saw were URLs in <a> tags and img src tags. For some reason they also changed Phone Numbers and added in some Javascript to log clicks on email address links.

Why are they doing this?

I am guessing it is part of a campaign someone is running.