We use twitter fast follow for work to allow people to get tweet updates right to their phone. Today we had reports that it wasn't working for some people. An error message came up reading "The FOLLOW command is no longer supported" We had those people try "f", "on" and "follow" and nothing work. We had numerous people test this issue and it doesn't not seem to be affected by phone type or carrier. Was their a recent twitter update or change to this service?
I trust that Twitter will make this right and come up with a resolution that is fair.