Facebook 'listening' claim denied by professor
Prof Kelli Burns has denied saying she believes Facebook is listening to people's conversations via the microphones on their smartphones.
In a news story that went viral this week it was reported that she had said key words around her phone which then appeared on Facebook.
Prof Burns says there was a practical explanation for what had happened.
Facebook has previously told the BBC it does not allow brands to target advertising based on microphone data.
"Some recent articles have suggested that we must be listening to people's conversations in order to show them relevant ads. This is not true," Facebook said in a statement.
"We show ads based on people's interests and other profile information - not what you're talking out loud about."
Prof Burns, a social media expert from the University of South Florida, sat with a reporter from US-based News Channel 8 and mentioned African safaris and the car brand Jeep.
When she checked her Facebook news feed, the first post on her timeline was from a friend who had written about an African safari which someone had commented on three hours earlier.
"Nowhere have I heard anything about Facebook serving you your friends' posts based on what you are saying or Googling," she said.
"This friend has a lot of friends, and gets a lot of engagement, it's no surprise that it would be at the top of my feed."
She also saw an advert for Volkswagen, which is the brand of vehicle she owns herself.
"Although the angle of the story was supportive of the idea that Facebook uses the microphone I never made the claim that I believe that is happening, or that my one experiment with a reporter was in any way proof of that happening," she added.
She said she feels the story has been "blown out of proportion" but that she has since heard from other people who believe it has also happened to them.
"I believe there are a lot of strange circumstances and coincidences out there and people are looking for those," said Prof Burns.
"The fact that this story has gone global says a lot about people's concerns about privacy.
"I am not a scientist or a privacy expert - but I never said in that story that I believe Facebook can hear you."
Earlier this year, the BBC performed its own experiment with several Android smartphones to see if it was possible to turn them into eavesdropping devices.
Security experts managed to create an app that could listen in to conversations for prolonged periods without draining the phone's battery.
When quizzed, both Google and Facebook denied that they would use such a capability to tailor adverts and content for users.
Facebook also said that its ads are based only around information shared by members on the social network and their net surfing habits elsewhere.