How did ShareThis get on to my computer? Your nuisance shows up only on one web site and, apparently, only on one page on that website (Comunn Eachdsraidh Uig). The biggest problem is that your on-hover doesn't turn off when I close the window. I'd rather not see "sharethis" at all, but as long as I can close it and have it stay closed, it's (barely) tolerable.
It may be hard for you to comprehend, but I an mot on any social networking sites at all and have no intention of joining any. Therefore I have no possible need for sharethis.