Part of the conventional wisdom in having tech companies apply for lots of patents is that they're helpful as a "defensive" mechanism against other companies filing patent lawsuits against you. It's the nuclear stockpiling
argument that suggests (without much proof) that the more patents everyone holds, the less likely actual patent litigation will result. That doesn't seem to be happening, though, as we see more and more patent "nuclear wars" happening. For example, Alcatel-Lucent went after Microsoft on a questionable
patent concerning MP3 technology. While Alcatel-Lucent initially won
that battle to the tune of $1.5 billion, everything's gone down hill since then. First, Microsoft hit back
at Alcatel-Lucent, dredging up a bunch of patents it claimed the company was violating. Then, a judge overturned
the $1.5 billion ruling. Now, Microsoft's patent attack on Alcatel-Lucent has succeeded, as a judge at the US International Trade Commission (yes, Microsoft is also using the popular loophole
in patent law here) has determined that Alcatel-Lucent has infringed, suggesting that its products be barred from the US
. While this seems like a silly ruling, it does show how if you're going to play the game of accusing companies of patent infringement, you might get burned yourself.