Staffa - 9:02 pm on Dec 29, 2011 (gmt 0)
The thought that all SEs will take your attitude as the green light to employ such behaviour worldwide makes me shudder
It's rather you who are giving the SEs the green light by not having a 'crawl-rate' in your robots.txt. Since there are no restrictions they are given the green light to crawl at any rate they wish.
Put a crawl-rate in your robots.txt file and any IP of SEs that do not conform redirect them to said file for a number of hours, it obviously needs time to memorize the content.
It works for others, it may work for Bing as well.