Webmaster disgraces website owner over 1050€ debt

English translation:

This gentleman [...] owes 1050€ (1358$) to this guy [...] For which reason: This website [...] and related mail boxes will be OFFLINE until the transfer of the entire debt will be made:

[... bank details ...]

Until the payment, any kind of communication from and to me will be interrupted.

This is never a good move. It's a legitimate issue but I think in the long run the developer will lose more in business.