bill - 5:15 am on Feb 12, 2013 (gmt 0)
Not irrelevant here is the pot calling the kettle black aspect. MS pretends they do not scan my email for keywords, even though they do.
Just to play devil's advocate a bit here... that's not the issue in this case. Every webmail and ISP that has AV or SPAM services looks at the content of your mail in some way. That's expected or understood in most cases.
The HUGE difference with Google is that they do scan your mail to focus their advertising. No other webmail service does this. The important difference is that when Yahoo, Microsoft or your local ISP scans your mail they are doing it as a service for you (to cut down on SPAM, etc.). When Google does it like this it is only to pad Google's own pockets and feed their advertising machine.
Even though Google does this with the best intentions, and it may be true that humans aren't reading our mail in most cases, how can we know that? Individuals are concerned about governments and corporations infringing on privacy rights so this is an approach that may have some effect for Microsoft.
The simple fact of the matter is Google scans our mail in a manner that other services don't. It's fair-game for MS or any other competitor to point out this out.