Taz Crawlers From China

Continuing with experiences on the net another thing I have noticed are crawlers  operating from China (at least that is what their originating IP addresses are from). None are well behaved and ignore the robots.txt file, some are well written insofar that they are efficient, but most are not and will download anything and everything usually multiple times. I call those Taz crawlers (think Tasmanian Devil) for what should be obvious reasons. We block all these crawlers.