Notes

Josh- Because he hates me, and wants to break me down before going to college. Very likely, as he is leaving soon, and wants to get the "last laugh" before going away for good. To deal with him, I would have to make sure it's not in the car or in Dad's memory. After that, I search everywhere, then take the charger and something else that is valuable to him. Then I have to confront him about it. If he doesn't give it back, then I won't give his stuff back.
Hannah- Because she despises me or the videos for some reason, either out of jealousy or embarrassment, but due to her fake facade, it's hard to tell. Likely, as I get a strange feeling from her, but I'm really not sure. To deal with her, I have to make sure it's actually her. I actually would love to fight with her, because I just want to hate her. Might take her phone, but most likely something else that is kind of valuable to her.
Dad- Because he wanted to store it and keep it safe. Unlikely, because if he did, he would probably tell me.
Mom- Highly unlikely.
Accident- Because it somehow slipped out of the camcorder. Unlikely, you can only open that side of the camcorder with your finger, and not by doing nothing, so there's no way it just fell out.
Paul- Because he was playing around with it, took it out, and forgot. Unlikely, if it was before the trip, but for during the vacation, there's very little chance.