38 - 900! Those who aren't too greedy can sometimes get away with hitting obscure but important keyword combinations for quite some time without anyone noticing.
I've seen some web design/seo/hosting companies use a good method - and they only grab ONE SERP with cloaking. Usually not number one, but in the three-four-five range.
I reported one such case about a month ago, and google had them dropped within about a week. The hosting company had a submdomain back up and listed the next time I checked( I thought that was pretty impressive ), with a loss of about 4 positions -- this time with no cloaking. I was only watching a particular demographic location/market; I assume they use the same method for many markets, but never checked.
I don't report these things to wipe the competition, but so that the search engines can study the methods and create successful filters.
It's really all in a good spirit, provided that those trying to beat the filters are still relevant for the key terms targeted.
Tyring to capture eight hundred positions, however, is likely a bit overboard.