lucy24 - 8:24 am on Jul 24, 2011 (gmt 0)
have you checked your server access logs to see if Googlebot-Image has accessed robots.txt since july 5?
Do you know, until you asked I hadn't realized that the imagebot makes its own visits to robots.txt. I went back and did a rough count. (Thank you, text editor.) The imagebot has picked up robots.txt about ten times since the restriction was added. The particularly interesting part was that on the day before its flurry of 403's it read robots.txt three separate times-- it never does this-- followed by one more time earlier on the day of the 403 binge.
i would add a specific rule for the image bot:
And you know what happens then. You have to go back over all your other rules and repeat them: "googlebot, this means you too". Hm. Well, that's another use for Regular Expressions.