The only thing I've been able to find that refers to "topbar-social" is this, from the stylesheet.css:

/* ==== Header CSS Additions ==== */

#topbar-inner ul {margin: 0; margin-left: -40px;}
#topbar-inner li {display: inline; padding-right: 5px; padding-left: 5px; border-left: 1px solid #fff;}
#topbar-inner ul li.first {border-left: none}
#topbar-inner a {color: #fff;}
#topbar-inner a:hover {color: #fff; text-decoration: underline;}
#topbar-welcome {float: left; width: 350px;}
#topbar-social {float: left; width: 225px;}
#topbar-cart {float: left; width: 200px;}
#topbar-search {float: left; width: 225px; margin-top: -5px;}
#header-bottom{}
#header-logo{float: left; width: 525x;height: 100px;}
#header-right {width: 450px: float: right; text-align: right;}
#languages {float: right; padding-top: 3px;}
#languages img{vertical-align:middle;}
#currencies {float: right; padding-left: 10px;}
#header-navigation {height: 40px; line-height: 40px; font-size: 20px; font-family: Times New Roman, Times New Roman, Times, serif; font-weight: bold; display: none;}
#header-navigation ul {margin 0; margin-left: -50px}
#header-navigation li {display: inline; padding-left: 10px; padding-right: 10px; border-left: 2px solid #ff0000;}
#header-navigation ul li.first {border-left: none}
#header-navigation a {color: #fff;}
#header-navigation a:hover {color: #ff0000;}

/* ==== Main Page CSS Additions ==== */

I haven't been able to find <div id="topbar-social"> anywhere.