Yabba, Dabba … Don’t?

What if, while riding the Metro, between shuffling songs on her iPod and reading the free daily, a young college student spots an ad encouraging the fight against global warming. This girl, an activist at heart, would like to donate, but the truth is that she can barely afford her school books. But then she reads that she can text in her $1 donation, which will be added to her next cell phone statement. Which works out perfectly, since her parents pay that bill anyway.