_You_ may not have, but plenty of us have. Although, it's not as important when or how many times one has _needed_ to exercise one's freedoms, as it is to have them. But yes, plenty of us open-source users and supporters have exercised this very freedom. In fact, quite a lot of open-source contributions happen _because_ of this freedom: someone has an itch, they scratch it, and _then_ they upstream it.