@Questioner,
Over here we pay our taxes on the stake, not the winnings. It used to be that you were given the choice at the betting shop, (though not with lottery tickets) most people chose to pay on the stake.
Regarding paying taxes versus charitable giving, JB Priestley covered the matter very well. Perhaps the cruelest person in the play was the head of the charity. If people pay enough taxes, we don't need charity. That's basically the Socialist argument, you either agree or disagree with it.
Om Sig Dave definitely agrees with the argument, as if sure he'll concur.