I wanted to buy some YAC, and Oldsport gave me an offer of 5.5BTC per k YAC. He told me he is a trustworthy one by giving me a web of trust link for reference (http://bitcoin-otc.com/viewratingdetail.php?nick=oldsport).

I was too careless that I trusted him and send him 15.599+ BTC for buying 28363 YAC, with the following transaction:
https://blockchain.info/tx/3816f40c21fcbab2c63fce34830f36bc5e5ce395a79c4a33a1ba5632cebad5ce

my YAC address is Y6esKzen4ZRgemm1egkb5EdWJVFKgM6P56,
Until now, I haven't receive any payment.

However, he has showed up before I wrote this scam accusation in this thread:
https://bitcointalk.org/index.php?topic=201003.0

I'll try to take some snapshots of the pms and upload them. Admins can check if they are true.