I understand. I knew it would be an uphill battle, and so I'm not making too big of a deal out of it and screaming my head off, but I figure it'd be nice to at least claim the 5.16 BTC and have my name on there or be refunded (if possible).
So unfortunately I'm kinda newb here, so how do I sign a message to prove that it was my bitcoin address that sent those funds? I'm not sure how to demonstrate that it was my bitcoin talk account on here who paid in, but you can see in Page 1 that I expressed interest early on and pledged 5 BTC.
Maybe Ragingazn can confirm, but here's where I messaged him right after paying him:
http://imgur.com/ElyqsCqHere's my MtGox screenshot:
http://imgur.com/BvwDO9LI know as you said screenshots are insufficient, so I did message JohnK (waiting for response). Perhaps we can work something out regarding MtGox access. I'm cautious when it comes to these things like access, but hopefully we can work things out.
Signing a message isn't possible if you sent the funds via MtGox as far as I'm aware. You need to send from a proper bitcoin client I think, because MtGox uses different sending addresses every time you send funds and doesn't give you access to old addresses.
I also don't think you'll be able to demonstrate it was your bitcointalk account that paid - if you had posted using the name dmo580 at the time that you'd sent payment, people would probably give the benefit of the doubt (if no-one else claimed it), but it's now so long after the fact that anyone could claim it was them. The fact that you pledged funds helps, but there was no confirmation that you'd sent funds from you or anyone else. Unfortunately ragin has lost the trust of many of the people involved in this group buy, so his testimony one way or the other will do little to help you I fear.
Your best bet is to let JohnK into your MtGox I think - if you're worried about security, just make sure your account is empty before you let him in. Withdraw everything, then all he can do is see your transaction history (and you can change your password afterwards). This would also protect him from accusations of stealing - if you post on the forum here that you have withdrawn everything, and then you PM JohnK your account details, he can log in and even if you claimed he stole everything afterwards, no-one would believe you. So he would be safe, and you would be safe. Only do this if he agrees to that procedure though.
Having said that, JohnK is probably the most trustworthy person on here, so personally I wouldn't worry too much about him stealing anything if I were you. The important bit is to get his attention. Once you have gotten his attention, be patient as he will probably deal with you last because there are many refunds to send, and the others are much simpler for him to process.
Good luck!
scotjam
JohnK - if you're reading this, to my untrained eyes, the MtGox screenshot provided by dmo580 seems to corroborate his story that he paid 5.16 btc into the pot, and the transaction history of the escrow address seems to agree. Therefore I would recommend further investigation of this matter as either he is a sophisticated scammer, or he is honest and significantly out of pocket.
EDIT: JohnK - you may also be able to check that dmo580 did actually send a PM to ragin to verify he sent payment, with the transaction ID bc4ed5d44166100127dfacf04ffbdc4385e5c1fe19325118e3c4666ec3421156 - maybe that would be sufficient? I'm not sure to what extent you can access other people's PMs...