How are you defining monopolies? Companies that are successful? Because you seem to be defining most US companies that do business in Europe as monopolies. It seems that this is the kind of mindset that has kept Europe behind. Too bad. Regulation that keeps out competition or needlessly puts obstacles in place is bad for the consumer, bad for employment, and bad for the general standard of living. And If you think US companies are unregulated then you haven't seen the 20 ft of federal CFR regulations together with the regulations of 50 different states that US companies have to deal with everyday.
Monopolies are one-two companies that capture the market and lobby the government to fortify the regulatory capture via:
1. regulatory bloat, artificial increase in cost of business to prevent new competition
2. lack of anti-trust enforcement, government fails to protect the consumer and instead protect the monopolies' income