Re: Bookmakers Not Paying Customers
Happens all the time with smaller outfits. A few are scam artists, most are just perpetually on the edge of going broke and trying to save a bit.
With heavily regulated British/Aus books, it's fairly rare. Even when they do, it tends to be a bit more organised. I had an Aussie book go bust on me, got all my money back because all their deposits were covered in escrow. A UK-based book also, they shut down, paid out no problem. Neither was serious money, a few thousand, but as far as I know everyone got paid from both.
By contrast, I had money in a book based in Malta (a lot of smaller European books are based there). Owner disappeared, I lost 5k euros.
Other than that, you're largely relying on reputation and size. All the pro-focused books (Pinnacle, SBO, IBC) are serious outfits. Of the recreational ones, party/bwin are large, as are the British ones with lots of physical shops (Ladbrokes, William Hill, etc).