The Electronic Outpost Foundation (EFF) has launched a research project called Panopticlick to investigate seemingly innocuous browser configuration information, such as user agent strings, plug-in version numbers, fonts, and so on, to create unique digital fingerprints that allow web surfers to be tracked, Even if the cookies are restricted or deleted.
According to EFF's findings, the average browser sends 10.5 bits of information entropy (the browser type that sends the most messages is: BlackBerry 14.7-15.5 bit, Android's 14.4-bit, ie's 13.2-13.5 bit, Debian's 13.5-15.3 bit), This means that one person in the average 1500 (2^10.5) has the same user agent string as you. Eff that this is not enough to protect the privacy of the user, especially if the information is combined with other information such as geographic location or postal code or an uncommon plugin for installation, the user agent string will become a real privacy issue for users.