A Can of Man

I feel ya TOG. The problem is a lot of the sources I know are actually personal.
As with Chupike anyway, if you say you drank water in front of the Lincoln Memorial, you have to provide the molecular formula for water and sufficient proof that it is drinkable (and that you would survive drinking it) and that you actually had a drink on that particular day and in that particular location (I guess by holding up that day's newspaper or showing your cell phone with the date clearly visible with a local landmark behind you).
And maybe DNA evidence and something else for that matter to prove that it wasn't a body double and some sort of guarantee/evidence that the newspaper and the cell phone screen were not photoshopped in any way. Also that the background is in fact, not a blue screen job.