As per the article i linked to – you can use the ID to get the nicename for example. then you can use that as your condition:
// Get author ID outside of loop
global $post;
$author_id = $post->post_author;
// Get author nicename
$author_nicename = get_the_author_meta( 'nicename', $author_id );
if ( 'Fred' == $author_nicename ) {
// do your stuff for Fred
}
If you have a lots of authors, and each of them have their own social links, then i would recommend using an Author Box plugin that supports social links.