As somebdoy who is currently trying out you.com at work, I'm interested to know what their rationale for this is. Meddling in the DOM of third parties requires

As somebdoy who is currently trying out you.com at work, I'm interested to know what their rationale for this is. Meddling in the DOM of third parties requires a good reason! I have a bunch of extension installed who I want to do this. But you.com is not among them.