I love critical thinking as much as the next person, but I always find statements like this to be smug and self-congratulatory cliches. Of course you take things at face value, we all do. Every waking hour we're getting new information and having to make sense of it, while still living our lives. It's not practical for anyone to pretend that every interaction can be rigorously confirmed and independently verified, which means proliferation of convenient, effective mechanisms for lying and deception should be of real concern to all of us. No one is such a great critical thinker that they're immune, and it's particularly dangerous when our few reliable avenues of verifying identity and provenance are about to be cut off.

The problem isn't about the ones who already critically think.

This is going to be increasingly key. And even then, it will be very difficult.

Books like "Trust Me, I'm Lying" reveal the lengths at which deception can occur. Though this book discusses deception that starts at the textual level (e.g. blogs), it is inevitable that these tactics will be translated to the video level once the technology catches up.

Also, "at face value" - Ha! ;)