Australians are becoming more guarded in what they share on their Facebook page as lists of friends grow, local media agencies say.
A monthly survey of 1000 Australians by WPP AUNZ has found anecdotal evidence that Facebook users are worried they may regret what they share in years to come, particularly as they are likely to now have hundreds of friends on the 12-year-old platform. 
The news comes as analysts warn that regulatory uncertainty on privacy issues clouds the company's global ambitions even as it leads Google in online display revenue helped by its "unparalleled capabilities" to profile users and identify them across devices.
The increased reticence of Australian Facebook users to share personal information, which WPP has noticed since it began its FutureTrack survey in   November, tallies with habits already noticed in the US, where Facebook is working to combat a decline in personal sharing, which is key to its attractiveness to advertisers.
Personal preferences, revealed by details such as a bar or restaurant which one of Facebook's 1.6 billion users has gone to, can give advertisers and media agencies a more complete picture of an individual's potential buying intentions.
But the rise of Snapchat, Facebook's Instagram and other messaging services such as What's App, also owned by Facebook, have created alternative ways to share personal experiences, preferences, photos and videos with individuals or more select groups of friends.
"People are still happy to trumpet the more day-to-day stuff with everyone through all their social channels," said WPP AUNZ chief strategy officer Rose Herceg.
"But I think people are seeing that what you give up too cheaply you regret. It seems people are rediscovering the joy of sharing with just one person: the face to face conversation."
Ms Herceg said the early signs of the trend were not necessarily to Facebook's detriment. "It would be remiss to think they don't have a huge team of people looking at this. It could be cyclical or generational, it may not be across the board for every demographic," she added.
This month Bloomberg reported Facebook chief executive Mark Zuckerberg had spoken at meetings about the need to inspire personal sharing. Facebook launched its "On This Day" feature last year which recalls memories from past years.