I have never done it myself, but I have seen it done. Some of them are folks who should not be using a saw anyway, like people who buy their saw at Wal-Mart. I work at Wal-Mart and do you know how many 2 cycle engines we get back that have been straight gassed? Not just chainsaws, actually string trimmers are the most common 2 cycle engines people try to return. Folks that know how to properly use a chainsaw do not shop for them at Wally world. The biggest saw we carry in my store is a Poulan Pro 4218, 42cc with a 18" b/c. A very typical homeowner saw that has little interest to anyone serious about saws. Not saying everyone that buys a saw at wal-mart is a guaranteed to burn it up, but it has been the largest majority of my experience. Things do seem to be getting better now that there is the quarts of 40:1 fuel, that we place right beside every 2 cycle engine we sale.
On a related note. I actually watched my uncle straight gas a new Husqvarna 50 special in the early 90's, it was the second or third tank of fuel. He reached in the truck bed, grabbed the can and filled er up. The ding dong had his mixed fuel and straight gas in identical containers and neither was marked. That is when I learned you bring your mixed fuel and leave the can of straight gas at home. I always keep my straight gas in a 5 gallon can, no matter how much there may be. The mix stays in either a 1 gallon or a 2 1/2 gallon can, depending on how much cutting I am planning to do.