Officials of the United States and other countries have long pushed to expand their access to newer forms of communications to resolve an issue that the FBI calls the “going dark” problem. The changes to online chats, which are written messages conveyed almost instantaneously between users, result in part from technical upgrades to Skype that were instituted to address outages and other stability issues since Microsoft bought the company last year. But that barrier could eventually vanish as Skype becomes one of the world’s most popular forms of telecommunication.

Surveillance of the audio and video feeds remains impractical - even when courts issue warrants, say industry officials with direct knowledge of the matter. Skype, the online phone service long favored by political dissidents, criminals and others eager to communicate beyond the reach of governments, has expanded its cooperation with law enforcement authorities to make online chats and other user information available to police, said industry and government officials familiar with the changes.

Blocking ads on skype