Comcast internet went down for me starting Tuesday and it hasn't come back up yet. We had a snow storm and all but I can't think what kind of a problem that could cause that couldn't be fixed in a day.
EDIT: Turns out it wasn't an outage at all. My connection was being blocked because I had Comcast change the plan on my account and modem had to be re-registered. It would have been nice if the customer service rep who changed my account had let me know what to expect.
EDIT 2: On the first two calls to Comcast, automated messages informed me of an outage and some sort of maintenance work. I hung up without talking to a rep, assuming the problem would be resolved.