[barredo]

What I think:

It's ok for Apple, Microsoft et al to defend themselves if Android violates their own patents.

It's not ok for Apple, Microsoft et al to defend themselves if Android violates patents they didn't develop.

Also, remember that although Microsoft & Oracle claims that Android violated some of their software patents, Apple claims against Samsung go far beyond that, this analysis by Nilay Patel is pretty good: http://thisismynext.com/2011/04/19/apple-sues-samsung-analys...

[aphexairlines]

All patents held by companies were bought from someone else. They're just usually paid for with salaries.

[pkamb]

So you want to prevent some poor independent hacker from selling his patents to large companies?

[petervandijck]

If the patent system worked correctly, that would be true. But it hands out heaps of trivial patents, so not even that.

[doe88]

I concur. But it brings an additional question:

Is it right for Google to defend itself with patents they didn't develop? (like for instance those bought from IBM)

In this case I think not.