Teens most of the time. They are the ones who can decide what they want to do so mostly they end up gambling just so they could double their allowances.
The problem is, gambling sites are open to anyone and so they will try to use the credentials of those around them to take advantage of it.
Governments must be aware of this and I know they have the numbers to prove that most gamblers in this era are teens. As a individual, all we could do is warn the people near us, but when it comes to national problem the government must also do something to percent this kind of schemes from happening over and over again.
I doubt this will ever happen, since long time ago governments have stopped caring about their citizens as persons and they only see them as economic agents which produce and redistribute wealth, and when a government looks at persons this way then they could care less about a bunch of teens gambling, and instead what they care about is the gambling industry to keep reporting huge gains every single year, as the gambling industry is heavily taxed and they get most of that money for themselves.