A number of New Zealanders are concerned about data sharing, unless firewalls are in place.
Results from a Privacy Commission survey shows nearly half of all Kiwis are still concerned about what they put online.
Privacy Commissioner John Edwards says sharing data between agencies is necessary for many organisations.
"People are not inherently opposed to sharing personal information -- agencies sharing personal information to provide better services. But those agencies have got to do the work to ensure that the data is going to be safe."
Around 80 percent of respondents were also sensitive about the monitoring of personal phone and email conversations.
The survey comes as Privacy Week kicks off, and Kiwis are being encouraged to rethink how much personal information they share online.
Mr Edwards says there are ways for people to monitor data swapping between agencies.
"Everybody is entitled to ask for information. So if they think their DHB or their bank has been inappropriately sharing information, they're entitled to ask to get copies of it and to look at it and see exactly what's there."
The survey suggests myths surrounding young people's more relaxed approach to online privacy needs revisiting.
Mr Edwards says surprisingly the younger generation are growing increasingly concerned about the issue.
"I was a little bit surprised to see levels of concern among young people rising, because there is a bit of mythology that young people don't care about privacy, and clearly that's not the case."
Nearly all survey respondents were concerned about the personal information children upload to the internet.