Good luck with the petition. Petitions are usually a tough haul unless you get some national exposure. As one of the former conspirators
I have a different view. Governments naturally keep secrets since its less headache than trying to explain the truth to the public, like that they are not in control. Plus each nation is suspicious of all the rest and they don't want to give up any "advantage" that they perceive they have (you show me yours, I'll show you mine). Governments always have experimental stuff of their own and they want to hide that too. UFOs provide a convenient blanket. The government is not sure what the aliens want so how can they tell you?
Even Jimmy Carter, who admitted seeing a UFO himself and who said he would get the gov to open up, accomplished nothing. Same with Clinton. Same with Obama. DEMs always promise stuff to the UFO crowd then never deliver. Business as usual. But governments do need to keep some secrets so demanding the gov tell you everything is also not such a good idea. Having said that, I think people have a right to know at least the basic things about UFOs/Aliens: Are aliens visiting Earth? Are they a threat? Why are they here? Has the government made any deals with aliens?
I have my own theory about UFOs and its a whopper!