Legal status of Blockchain proof-of-existence TX (USA court) Is there any real USA court cases with Bitcoin's Blockchain used as an proof-of-existence/timestamp service (without BTC transfer)? 

Can Bitcoin's Blockchain be used as a 'signing' utility same as DocuSign service (for example) that conforms to ESIGN?

Thank you.
I am not aware of any cases, but based on the long delay in relevant cases concerning the fax machine and email (proof of delivery, timestamps, etc) I would not expect such a blockchain specific case law decision anytime soon.

Technology advances far faster than the law.