As Administrator of the petition I can see who has signed and I have noticed quite a few signed the one on my facebook page that I set  up originally but have not signed the one on change.org..  Once I was shown this site and how it keeps tab and will send to the one's who need to see it, I scrapped the earlier one.  If you have not signed this one please do or you want be counted.

Act Now Save the Sandy Hook 5 Arch Bridge change.org

you can google it or just search the above on facebook