From Paul Graham’s “Are Software Patents Evil?“:
Fortunately for startups, big companies are extremely good at denial. If you take the trouble to attack them from an oblique angle, they’ll meet you half-way and maneuver to keep you in their blind spot. To sue a startup would mean admitting it was dangerous, and that often means seeing something the big company doesn’t want to see. IBM used to sue its mainframe competitors regularly, but they didn’t bother much about the microcomputer industry because they didn’t want to see the threat it posed. Companies building web based apps are similarly protected from Microsoft, which even now doesn’t want to imagine a world in which Windows is irrelevant. …