Four in five social networkers are ensuring their profile can only be viewed by friends and family, says Ofcom.
The watchdog says this is an increase from just 48 percent in 2007.
Ofcom's Media Literacy report also revealed that web users in Scotland are the least likely to worry about entering personal details online, with 50 percent admitting they were not concerned about using their home address on the web, compared to just 23 percent of those in Wales and Northern Ireland.
More than two in five Scots also said they were happy entering their credit card details online.
One in three web users said they prefer to check their bank balance online, compared to 22 percent in 2005.
Furthermore, 36 percent of Brits said they booked their holiday online and 47 percent used the web to find out more about an illness.
Four in five also admitted to saving money in the past six months by shopping online
When it comes to the reliability of the content on the web, seven in ten Brits believe TV and radio content is more reliable, despite over half (58 percent) of web users claiming they trust news sites.
Nearly three quarters (73 percent) of UK adults used the web in 2009, compared to 63 percent in 2007.
The Scottish spend most time on the web, racking up 10.6 hours per week, with the English coming a close second with 8.3 hours a week.
The Welsh spend 6.8 hours online a week, while those in Northern Ireland surf the web for 6.5 hours a week.
However, a quarter of web users admitted they didn't feel confident when it came to setting up web filtering or other online security features.