OP seems to be a account farmer.
Check his last post: https://bitcointalk.org/index.php?topic=2372443.msg24212212#msg24212212
archieved: https://archive.fo/NkJoN

Here is the explanation why i changed my BTC address:
My private keys were been leaked months before which made it unsafe for me to keep that BTC address onto my profile. Perhaps OP was the one who got access to my private keys and now is trying to prove ownership to the account with those private keys. I had used those private keys in various places including some ponzi ICO schemes and perhaps from there my private keys were been leaked.

I have seen a lot of such peoples claiming to be the real owner of the account and may misuse such accounts. Also it has been made much reliable and accounts are safe here because we get a link to bann the account to our email if someone changes email. Real owners will always bann the account if the account is been hacked.

This is a another thread by a scammer who want to scam my account. I appeal and request DT members to tag OP.
I have also stopped doing any transactions from that BTC account as already it was been leaked.

Such kind of scammers are always having a look on good accounts and they claim false ownership with those hacked private keys by signing a message. It has been turned into a trend now and also some another alternative should be found out to keep "Real Account owners" safe.