Did you remember to file the SAR paperwork? It's required by US law if you're trying to withdraw more than $3K within 30 days.

Sorry, I'm not familiar with this paperwork. Could you point me in the right direction?

Its been over a year since I first asked for my BCH (in fact, I asked to receive my bitcoin from the multi-signature account months before that, but it was delayed due to technical issues with Coinbase's system at the time). Coinbase's agents initially told me that the engineers would eventually work on the issue, and I took them at their word.

However, I've waited for more than a year (far beyond a reasonable timeline), and they have gone radio silent since my message to them over 2 months ago.

I've only recently started looking into taking steps to find a lawyer and actually bring Coinbase to court.

Edit: I will probably file a CFTC complaint in the coming days. Not sure how helpful it will be though.

There is a long list of people who have been scammed by coinbase and the many other exchanges. I had about 12 btc in a bittrex (another "safe" us based exchange) account that I signed up for with a pseudonym. Then one day around the time btc was at $19k they decided to lock my account until I give them a selfie showing my passport and other scans of id. They know this is impossible and will not let me change my basic details (citing some sentence in their ToS and how they are trying to protect me). I went the lawyer route but it turns out there is nothing you can do legally if wording in the ToS says any deposits belong to them, they are not responsible for anything, can't be sued etc. Also no one really cares about bitcoin or other cryptocurrencies in the legal sense. So good luck trying to get your bch. This turns out to be a double edge sword because since then I have made use of some of the exploitable bugs in several cryptocurrency wallets held on exchanges and have transferred back the amount I lost plus much more. Didn't even bother to use a proxy or anything because I know there is nothing that anyone can do about it, go ahead and send the internet police to my house maybe that way I can finally get in contact with them to investigate the btc that was stolen from me.

No, it isn't. SAR is a form that a bank files if a transaction meets certain criteria. The customer has nothing to do with it.

I don't get it. If it is a multisig, you have 2 keys out of 3. You can do the deal yourself.

In Coinbase’s multi-sig system, there are three keys: a user key (which I have), a shared encrypted key (which is encrypted with a password that you can access on Coinbase.com), and Coinbase’s user key. Without going into too much detail, I misplaced the shared seed password, and needed to withdraw the bitcoin with Coinbase’s user key. Coinbase had an issue with the multi-sig system at the time though that prevented it from providing its seed, so it took several months (during which the split occurred) before they sent me my BTC. However, I’m still missing my BCH (which corresponds to the same address), and need Coinbase’s seed to receive the BTC. I guess I could try to brute-force my user seed due to my password patterns, but that’s a last resort, since my BTC has already been sent.

Anyways, I recently called and got through to Coinbase, and the agent told me they will respond with more information over the next week. I’m putting any legal action on hold for the time being as a result.

If it was a multisig account, they don't have the keys. That was the whole point of that feature.

In Coinbase’s multi-sig system, there are three keys: a user key (which I have), a shared encrypted key (which is encrypted with a password that you can access on Coinbase.com), and Coinbase’s user key. Without going into too much detail, I misplaced the shared seed password, and needed to withdraw the bitcoin with Coinbase’s user key. Coinbase had an issue with the multi-sig system at the time though that prevented it from providing its seed, so it took several months (during which the split occurred) before they sent me my BTC. However, I’m still missing my BCH (which corresponds to the same address), and need Coinbase’s seed to receive the BTC. I guess I could try to brute-force my user seed due to my password patterns, but that’s a last resort, since my BTC has already been sent.

Anyways, I recently called and got through to Coinbase, and the agent told me they will respond with more information over the next week. I’m putting any legal action on hold for the time being as a result.