What's the point of requiring a title again?
It's a point well made, but that said relying on what Google is or isn't doing doesn't necessarily translate to what anybody else is doing.
That said I think all of us who have developed OSS software large and small have seen this from the communities at large in code, support and monetary terms. It's hard giving up your time to keep developing, living on noodles and water, in what becomes a full time job with often little reward but the knowledge your code is out there doing it's thing on x thousand servers. It's why I quit doing it full time and only develop OSS on my timetable for my needs - but if everybody did that some great projects just wouldn't exist.
And yes it's always tends to be the guys who are the most militant about open source who are the worst offenders.
All that said I think we all know who the worst real-world corporate offenders are for this. The company that shall remain nameless who have BSD at the centre of their OS, but aren't compatible with anything anywhere. This is the same company who will charge Open Source developers trying to give a damn and fix issues that are specific to their OS - for the privilege of talking to anybody who knows their codebase.
Even Microsoft do a better job than this nameless company, Microsoft are only too happy to talk to Open Source developers about any subject, be it their code, your code or some guys from Redmond discussing (complaining about, actually) the availability [or lack] of porn on the iPhone (no joke this actually happened to me).