Google claims to be open when it suits them - when they're about to launch their own operating system that will go head-to-head with Microsoft Windows.
When it comes to their own search and advertising algorithms - their real money earners - though, they are perfectly happy to be absolutely "closed".
Of course, Google's defense is that if they were to open source their search ranking algorithm, spammers would swoop in and make a terrible user experience.
And if Microsoft did the same, and a bunch of hackers and spammers swooped in and took over control of our PCs wouldn't that be a much, MUCH worse user experience?
Google needs to just face the facts. They're happy to make tall claims so long as it doesn't affect their real revenue stream. Where it comes to their real bread and butter, though, they protect it with cloaks and daggers.
In reference to:
"The meaning of open"
- Google Public Policy Blog: The meaning of open (view on Google Sidewiki)