リファラを消す

a.onclick = function () {

     //remove referer

    this.href = "data:text/html;charset=utf-8," + encodeURIComponent('<script>\x3c!--\ndocument.write(\'<meta http-equiv="refresh" content="0;url=' + this.href + "\">');//--\x3e\x3c/script>")

}