Enforcing trademarks another example of a social program for business that I guess you could live without. We could disagree about the need for patents and how the US Patent and Trademark office is configured, but most people here, among them entrepreneurs, would agree that trademarks are a good thing, and that they should be enforced.
But let's see what happens if we were to hijack each other's brands. Maybe we should take over the YCombinator trademark. After all, enforcing trademarks isn't directly concerned with national defense. In the name of limited government, it's OK to suggest affiliations with corporations by using their trademarks without their approval. Especially since we dyed-in-the-wool libertarians don't believe in negative externalities, and that businesses have the right to do whatever they want. Those other companies with their putative concerns about reputation and perception about their brands, trademarks and logos are third parties to the exercise of our God-given libertarian rights. I only hope my militia is stronger than their militia.