Certificate Authorities regard it as a badge of the trade to offer their main websites over SSL. However, John Airey points out that several CAs have not checked that the SSL versions of their sites can be used without generating errors. Verisign and Baltimore's sites both give warnings, and in some browsers so do Geotrust and Globalsign. This occurs because the sites include links to offsite images, but these images are only served over HTTP, causing browser warnings about insecure content when included on an SSL site. The point may seem small and obvious, but inconveniencing users by triggering warnings makes it more likely that they will turn off the warnings, which reduces their security.