Since its IPO earlier this month, Facebook has wasted no time in expanding its empire — it’s already purchased the Karma mobile gifting service and launched a standalone camera app – and talk about the social network’s next steps doesn’t seem to be quieting down. The latest rumor, from Pocket Lint, says Facebook is looking to buy the Opera browser as part of its larger effort to compete against Google, Mozilla and other internet mammoths. According to a source at Opera Software who spoke with Pocket Lint, the company is shopping around for potential buyers and has even imposed a hiring freeze. While it’s not too hard to believe that Facebook is readying its horse to enter the browser race, this rumor is just that: a rumor. But given the social network’s tendency to whip out new features at warp speed, we should have something more solid than speculation soon — if the Opera purchase story has any legs, that is.