CSS: visited's privacy protection, cssvisited

CSS: visited's privacy protection, cssvisited
CSS Pseudo-class (Pseudo-classes)

Pseudo-anchor: In browsers that support CSS, different links can be displayed in different states, including activity, accessed, inaccessible, and hovering.

a:link{Color: # FF0000}/* unaccessed link */a:visited{Color: #00FF00}/* accessed link */a:hover{Color: # FF00FF}/* move the cursor over the link */a:active{Color: # 0000FF}/* selected link */

The use of a label often uses pseudo classes to change the style, such as the background after hover hovers, font-size font size, text-decoration text style (none underline ), color font color, but under: visited, it cannot be changed.

1 <! DOCTYPE html> 2 
The reason is: visited's privacy concerns privacy protection. Original article link
Many years ago, CSS: visited was a way to query user history. It does not have any threats, but when it is associated with getComputedStyle () in js, you can use your history to find where you have been. Its speed can reach 210,000 URLs per minute, so you may get a lot of historical information or print your identity through fingerprint. Because browsers can save historical records for a long period of time, this method can expose a considerable amount of browsing information.