Samizdata - 7:32 pm on Mar 29, 2012 (gmt 0)
So far I haven't seen the bot to access css or js in my logs
The user-agent used for checking restricted files is never Googlebot.
But the IP addresses of the non-indexing stealth bots that do it are Mountain View.
Google has done this for years, but I can't remember Matt Cutts ever talking about it.
If he is now asking webmasters to make changes to help his company combat spammy results, as I believe he is, then saying so directly would be a much more honest and sensible way of going about it.
And put it in Webmaster Guidelines, not on YouTube.