I get pinged often about removing linkshells from a character profile because they are no longer in them. This used to be managed by the linkshell community. I added a section in your character edit page to remove yourself from any linkshells. http://www.ffxiah.com/members/
You will be automatically added to a linkshell if you use Guildwork Plugin. Currently, this is the only reliable way to get added to a linkshell. It could also be used to remove any old linkshells.