Google Wallet has had a tough go of it lately, facing security problems, rejection by cellphone carriers, and competition on several fronts. It's also had to contend with several team members leaving the project, and now co-founding engineer Rob von Behren is on his way to payments rival Square. NFC Times reports that von Behren revealed his new employer on his LinkedIn profile page, and that while he'd left the Google Wallet team earlier this year, he had anticipated staying at Google working in different capacities. "After meeting the team at Square, however, I decided to do the opposite," he told NFC Times. "They have a strong leadership team and a culture that fosters innovation."

The move is just the latest round of brain drain to hit Google Wallet. The project's other co-founding engineer, Jonathan Wall, left earlier in March along with project lead Marc Freed-Finnegan to form mobile-payments venture Tappmo; several other Google Wallet project managers and the project's director of engineering are also said to have departed. Part of the problem, according to NFC Times, is alleged tension between the original Google Wallet team and Osama Bedier, Google's vice president of Google Wallet and Payments (previously at PayPal, Bedier joined Google back in February of 2011). While it's far too early to say Google Wallet is in any sort jeopardy — Sprint plans to release at least 10 new Google Wallet-enabled phones by the end of this year — the constant exodus can't be good news, and with von Behren's move perhaps telegraphing Square's entry into the NFC arena, we expect things to get even more competitive in the months to come.