How many days after realizing that SMS wallets are starting to catch on before texts to and from the SMS wallet provider's number are blocked? (and thus the user's funds left stranded, at least temporarily). Unlike bitcoin's peer-to-peer architecture, telecom infrastructure operates as the givernment instructs them to.
This problem may be a little overstated. Governments don't always act so efficiently, and they'd have a tough time blocking us in such a way. Assuming we go international through a series of phone numbers in different service areas, it would be quite easy to get new numbers for any given service area. The local gov. and mobile service provider would be playing whack a mole. What's more, I'm sure the people would have something to say about it.
Good point. This reminds me of the Chinese govt vs Tor IPs. Most governments have nothing close to the systems set up by the Chinese, and even they're having a hard time. It also maybe possible to embarrass them in their favorite UN clubs or the world press if they start blocking numbers. I bet there are ways around the telecom guys stealing bitcoins, too -- anything from a separate one-time password device (could be super simple and cheap, even a printed card, especially because the individual transactions are mostly small) to some security questions, like "what's the 3rd letter of your son's name".