Skype on Thursday said that the majority of users were back online. CEO Tony Bates estimated to GigaOM that 16.5 million of the 25 million total simultaneous users could now login after Wednesday's worldwide outage. Voice as well as chat and video were back online, but conferencing on chat and video wouldn't be working for awhile as they were being used as supernotes for the peer-to-peer service, Bates said.