Virtual Casino Group has a notorious reputation going back several years ago. The Virtual Group primarily operates online casinos, but is known to run sports betting sites, such as the ones here.  They have been reported of locking player accounts without cause, withholding payments, spam, violating player privacy/personal information, and overall unresponsiveness.

Thevirtualsportsbook.net
Dreamsportsbook.com
Derbyhorses.com
Youwinsportsbetting.com
Weeklyfootballpool.com

Oyster Gaming, or Elka Systems Software, is associated with a large network of online casinos using their software.  Several sports betting sites are operated as well, including the sites below.  Evidence has been provided by a professional gambling statistician that Oyster Gaming Software delivered unfair odds in free play mode in at least one of their casinos.  The network has a reputation that is anything but spotless, and has also been associated with player privacy violations, such as giving away email addresses to spammers.  All sites using Elka Systems Software should be viewed with extreme caution and wariness.

Naturalsportsbook.com
On-play.com
Onlinesportscenter.com
Ownsportsbook.com
Sportsbetz.net
Sportsbook777.com
Sportsworld4all.com

Wager21 Software is reportedly a deceptive manufacturer that bestows gaming approval seals on themselves. A few online betting sites use their software, including the sportsbook below.  They have been accused of non-payment of winnings exceeding many thousands.

Luckydogsports

Cyberbookie Network has been accused of non payment of winnings several times. Management is also reported to be non-responsive and belligerent.

Metro Gaming
Ace in the Hole
Casino Pirata
KingdomCasino 

The following sportsbooks and internet sports betting sites have been accused of dealing in at least one, but sometimes several unethical and illegal practices.  Reported committals in one form or another include non payouts, intentionally delayed payouts, unresponsiveness, under funded capitalization, bankruptcy, player privacy abuse, fake logos, non-licensed & association with other sites of warning.

2001 Sports
Beat The Odds
Allied Sports
New Age Bets
Guardian Guarantee Corporation
Aces Gold 
GiGaming 
World Wager
TeleBet 
Oklahoma Sports Bet
Gamblers Palace
Arrowhead Sports
Best Bet Sports
Sports-Market
Bettors Book
BETZZ
Gambling Stadium
Fortress International
Golden 7 Casino
World Sportsbook International
Caribbean Sports
Sports Bet Online
Sports Haven
Mega Sports
Richmond Hill
Online-Sportsbook
Two for One Sports

1Casino
2 Wager Sports
Bring Me Luck
Sports Interaction
2for1 Sports
Players Bet 
Light Speed Sports
Aloha Casino
Crown Intertel
ESB 
ABetz
Celebrities Sportsbook
King's Bet
EZ Bets
Golden Wager
Casino Sports
Caribi
FijiSportsbook.com
Vegas Palace
Cayman Sportsbook
First Live Casino
Pyramid Sportsbook
Lucky's Casino & Sportsbook
Riverside World Sports
Video Las Vegas
theonlinebet.com
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