Internet Safety site and course feedback

Hi Khan Academy,

How can you exceed your own stellar standards to produce an even better version of Internet Safety?! I love the dedicated site and updated videos, and here's my detailed feedback.

First on the site: Great that you'd aligned it with KA's current playful visual language. No modifications needed, except a note that the course and all of KA are 100% free. I've added it to the blurb, quoted below:

Khan Academy interviewed Google's top security experts to bring you videos packed with powerful tips to help you stay safe online. It's all 100% free—Sign Up today.

I'm surprised the landing page mentions this nowhere. For first-time users of Khan Academy, it's super important to mention you're 100% free. Footer could link to KA privacy policy and terms of use, just like in any other page on the KA site. This is an online safety course!

Rest of the IntSafety landing page is fine, so moving onto the course itself. Thanks for featuring the intro video and description blurb in the course page, not just in lesson page. That's a much-welcome addition to the course.

Mastery-enabling the course is a welcome move, though I'm curious if you can add Mastery Challenge for just this one course. It's on Math already, and I know it'll expand to other disciplines, but Internet Safety needs those now!