1. Gambling in fact has many negative externalities. If someone gets addicted, the likelihood is much higher to be depressed. Depression is factor, which leads to high costs for the society.
2. Gambling addiction leads to economic costs because of crime actions. Other market actors have to increase their security standards, which means higher costs.
3. Many gambling addicts go as a consequence to jail. Jail means EXTREMELY high costs to society.
What are your thoughts on this topic?
There are quite a few external costs as you've highlighted and relatively few benefits, especially as winners who get lucky once have a tendency to pour it all back in. As with things like alcohol, as long as it is approached responsibly by an educated population then it can be fine. However the casinos and bookmakers should definitely play their part, by allowing people to self-exclude and preventing playing for periods of time when the behavior is erratic (such as jumping from a $10 weekly bet to a $1k daily bet). The government also needs to heavily monitor casinos as they have a long held reputation as an easy place to launder money because everyone is playing with cash.