Are internet Auction bids legally binding?

I need to find out whether internet Auction bids for real estate are legally binding. My brother needs to get out of a bid that he won on an internet auction because the deal seems too good to be true. The seller is however threatening to take legal action against my brother for backing out. Is this a legally binding contract even though nothing has been signed or even seen or is the seller just bluffing in order to scare my brother into sending him money?

[judg4]

Technically it is binding but frankly it is hard to enforce. And the seller has to re-sell before he can claim any damages,

World Law's lawyers could also probably intervene and help resolve this if need be. You may email them on the home page.