Ubisoft's uPlay, the online service largely used for validating the digital rights management on PC games, has been down for much of the day. If this is planned maintenance, Ubisoft didn't do a great job of communicating that to its user base, which is ripping the publisher a new on on its official forums.
Users have complained that they are unable to login to the uPlay PC client whatsoever, but they still are able to reset their passwords—it just doesn't let them in. One user posted the trouble ticket he opened about the outage and the reply included a link to instructions for deleting one's account.
This is an especially unfortunate time for such an outage as it occurs in the middle of the Steam Summer Sale. A lot of the forum anger comes from people who picked up a new copy of a game today and simply cannot play it. Some are offering workarounds to boot the game in offline mode, but most are venting their understandable displeasure.
If this is maintenance as opposed to an attack or other cause of the downtime, there's no estimate of when uPlay will return. I pinged an Ubisoft representative to see if we could get some answer as to what is going on, but being a Sunday, I wouldn't hold out much hope at this point.
Cannot Log Into uPlay [Ubisoft Forums ]