Final answer:
The secret group that formed in response to imposed taxes, protecting colonist rights and occasionally using violence, was known as the Sons of Liberty.
Step-by-step explanation:
In reaction to imposed taxes such as the Stamp Act, and in defense of the colonists' rights, a secret group formed that was known as the Sons of Liberty. This organization played a significant role in protesting against British policies and was famous for sometimes using violent methods to express their opposition, for instance, during the Boston Tea Party. The Sons of Liberty also included influential figures such as John Adams and played a pivotal role in coordinating activities like spreading propaganda and enforcing boycotts of British goods. They were known for the slogan "No taxation without representation," which encapsulated their protest against taxes imposed by the British Parliament without their consent or representation.