The Register reported in June 2008 that traffic from AVG Linkscanner, using an IE6 user agent string, outstripped human link clicks by nearly 10 to 1.[3] A user who revisits a site shortly after changing or upgrading browsers may be double-counted under some methods; overall numbers at the time of a new version's release may be skewed.[4] Occasionally websites are written in such a way that they effectively block certain browsers. One common reason for this is that the website has been tested to work with only a limited number of browsers, and so the site owners enforce that only tested browsers are allowed to view the content, while all other browsers are sent a "failure" message, and instruction to use another browser.[5] Many of the untested browsers may still be otherwise capable of rendering the content. Sophisticated users who are aware of this may then "spoof" the user agent string in order to gain access to the site.