I entered 'London Marathon' on Youtube to see what came up. The very first entry was called 'Flora London Marathon 2007' and had been described by the person posting as
"A hopefully inspirational video about the 2007 Flora London Marathon and a recognition of what makes it great".
All very serious and worthy stuff, until someone left the following comment. I've quoted it word for word, so apologies for the poor spelling:
"pease of piss try ultramarathons hard as hell ".
Although I appreciate that it isn't clever to leave comments like that, it did make me laugh :)