1) How do people think that bitcoin is actually anonymous? You would have to buy them with your debit card/credit card in which banks have your information... why would you think that this stuff is actually anonymous and could be used in such a way?
There are other fairly anonymous ways to buy bitcoin like from forum members or other face-to-face deals. After you have bought bitcoin, there are also means to loose the trail of your coins, making it harder for people to track your spending and ownership. Some would tell you that bitcoin is pseudo anonymous, I would say you can make bitcoin as anonymous as you need.
Just be careful buying bitcoins face to face in the US using localbitcoins. The newest fashion over there are undercover agents that are meeting people over localbitcoins and then arresting them and charging them. Freaking unbelievable!