Are Patents Killing Innovation?

Timothy B. Lee fleshes out his case against software patents in a new article:

[W]hile a small team of brilliant engineers can build some of the world’s best software, it has no hope of keeping up with big companies’ rate of patent filings. Patents threaten to turn Silicon Valley into a place where new firms must develop large legal bureaucracies before they can challenge incumbent firms.

Earlier discussion on this topic here, here and here.