You do get an option of what to display as the contributor. The message is the default, but there's a transparent option, as well as an option to show cat pictures instead of ads.
But it is very muted and I very rarely note it is there. Here's an example: http://imgur.com/28jjUjr
But it is very muted and I very rarely note it is there. Here's an example: http://imgur.com/28jjUjr