Two years after launching the most technologically savvy presidential campaign in history, Obama officials ran smack into the constraints of the federal bureaucracy yesterday, encountering a jumble of disconnected phone lines, old computer software, and security regulations forbidding outside e-mail accounts. What does that mean in 21st-century terms? No Facebook to communicate with supporters. No outside e-mail log-ins. No instant messaging. Hard adjustments for a staff that helped sweep Obama to power through, among other things, relentless online social networking.