This page has called for the re-enactment of Glass-Steagall for several months, so I might be considered and easy target for the petition. But I did not "sign" and I shall not do so. I've made it my policy to refrain from completing such petitions, not matter how sympathetic I might be with the position espoused.
I think that Internet petitions are at best misguided, that often they are misleading, and in some cases they may be misleading. In particular, I believe that many of them are directed less at expressing support for a position about an issue than to obtaining email and other personal information about the "signers." While the data may be intended for a legitimate, even laudatory purpose, how do we know? And how to we know that the information we volunteer will not wind up in the hands of people with whom we would not share it? We don't.
There's something else here: I believe that Internet petitions have no effect on political leaders. If I were a member of Congress, I'd question the legitimacy of the signers of such a petition--how do I know that they were not made up by the organizers--and would discount completely those who are not my constituents.
Internet petitions sound like a good and easy way to express opinions, but my advice is to ignore requests to sign them.