Thankfully I realised that it was a scam in time. I suspect that Malcolm MacDonald, David Baine etc are all really Ms. Chanunya Charugmano. It's this name that the $50 is supposed to be made out to. This is her address, so I think it's the Thai authorities that should be alerted, not the Japanese ones:

Korea ESL
MAP Pro Services - PMB No 129
7/1 Boromrajchonnanee Rd,
Bangkoknoi, Bangkok
10700 Thailand

If you look up Map pro Services on the internet, you will find that they peddle all sorts of unsavory stuff. If anyone in Bangkok wants to beat the hell out of this scammer, i for one would be greatful.