Taxes.
Paying taxes is immoral.
Taxes (and fiat currency) are used to support war and the murder/imprisonment of innocent civilians.
Using Bitcoin takes away part of that power.
Paying taxes is immoral - yeah - because you've never used roads before, or streetlights, or electricity, or not have to deal with terrorist attacks. What do you think your taxes go to? Taxes support war to protect YOU, and the murder/imprisonment of innocent civilians does happen but is extremely rare and is getting rarer and is much better than the alternative of keeping all criminals on the street. Please use a condom.
I pay for my electricity, no taxes needed.
Streets are supported by user fees. I have no problem with those.
I have lived in undeveloped areas of Philippines and Kenya, roads are usually built by locals without resorting to taxes. When I was young kid and part of some dumb religious cult up in the mountains, some of them got tired of there being no road. So a couple of them got together, pooled some money, hired a bulldozer, and guess what? We had a road without taxes or coercion.
As for the war on terrorism, I am more likely to get killed in a car accident than by a terrorist. A long time back, I went into the mountains with some girl I was planning to marry on Mindanao Island in the Philippines to meet her family. Discovered that her brother was in the MILF, he even let me shoot his AK-47 for fun. I never felt safer.
As for innocent people killed, I will just post a wikipedia link: http://en.wikipedia.org/wiki/Casualties_of_the_Iraq_War
As for condoms, I refuse to use them. Did make my Kenyan wife take an HIV test though.