[identity profile] bikinisquad3000.livejournal.com 2013-03-28 08:57 pm (UTC)(link)
As I recall it's a cartoon man and woman holding hands. Not quite the "men's room," "women's room" symbol ones, but close. I barely bothered to remember though, ha ha. I was just reading an article somewhere comparing the two userpics' popularity.

[identity profile] telemann.livejournal.com 2013-03-28 11:37 pm (UTC)(link)
The Archdiocese of SF made a Facebook icon using the division sign for traditional marriage or something.

[identity profile] usekh.livejournal.com 2013-03-29 03:25 am (UTC)(link)
I also saw one that was a cross

[identity profile] macychick.livejournal.com 2013-03-29 03:34 pm (UTC)(link)
I saw one that was the equal sign with a line over it- the "unequal sign."