The recordings leave users vulnerable to data breaches and leaks.
'This may expose users to identity theft, online scams, and other unwanted behavior.
They set up test pages, as well as analysing live sites, to find out what kind of information may be accessible via the tools.
Mr Englehardt and his colleagues identified four main vulnerabilities resulting from the use of the scripts.
But the Princeton team is concerned that keeping this data anonymous may prove difficult, exposing visitors to a number of dangers.
In a blog post revealing the findings, Steven Englehardt, a Ph D candidate at Princeton, said: 'Unlike typical analytics services that provide aggregate statistics, these scripts are intended for the recording and playback of individual browsing sessions, as if someone is looking over your shoulder.'Collection of page content by third-party replay scripts may cause sensitive information, such as medical conditions, credit card details, and other personal information displayed on a page, to leak to the third-party as part of the recording.
The team also created a searchable list of all the websites in their study that were found to contain scripts which could be used to record session, as well as those for which there was evidence of this taking place.