How did the colonists justify their protests and ultimate rebellion?

The Crown was using the colonies as an economic tool, so they imposed rough taxes without consent, and restricted its trading partners so Britain can make a huge profit. People in the colonies thought these measures (and others, such as quartering troopsand suspending local legislatures) were a huge violation of their rights [as British subjects], particularly because they weren't represented in Parliament.

Source: Hours of study in AP US History