These days most bookmakers try hard to be among the best in terms of seriousness and data safety. Still, from time to time world of sports betting is rocked by a scandal, which gave the industry a bad reputation. That is the reason why bookmakers must work very hard to prove their seriousness. Every serious bookmaker should definitely have valid gambling license. It often happens that unknown online bookmakers attract players with generous and mostly unrealistic bonuses and then simply disappears after sufficient number of players transfers their money. You should be careful before making any deposits and thoroughly check the bookmaker on the internet.