The primary reason that the colonists protested British taxes after the French and Indian War was because of "taxation without representation."
The colonists did not like to be taxed by the British Parliament and preferred to be taxed by their own colonial governments. They had nobody to vouch for them in the British Parliament and deemed it to be unfair. On the other hand, Great Britain said it was fair. They needed money in order to pay for the very expensive French and Indian War, which was fought on the soil of the colonists. They also were providing British troops to protect the colonists from outside forces. The colonists still did not agree with the taxing and said it was "taxation without representation."
Eventually, this would cause the colonists to boycott products that contained the tax on them. Sometimes this would become violent and British merchants and troops would get harmed. Great Britain would start doing searches of the colonist's homes and businesses, looking for products that could have been smuggled in without being taxed. This just ended up angering the colonists more, which eventually led to the American Revolution.
