The word I used was "volition", not "violation". (Sorry, I have a bad habit of using difficult words in my replies here!) "Volition" means "the act of exercising one's own will". If one does something "of one's own volition" then one chooses to do it, as in "I moved to London". In the passive voice ("I was moved to London"), something is being done to someone or something, rather than that someone or something doing it by itself. There
may be a sense of its being done "against one's will", but this is not necessarily the case.
The two further examples you give are similar to the first ones: there is not much difference between "was opened" and "opened" or "passed" and "was passed". When it's important to distinguish between something acting on something else, and something acting by itself, the active/passive distinction again comes into play. For example:
"The chasm opened beneath my feet" (nothing obvious was opening it)
"The door was opened for me" (someone opened it)
There are lots of verbs that work in a similar way: they can be used intransitively ("the tree shook") or in the passive voice ("the tree was shaken"). The general idea is usually the same (but there are no doubt some idiomatic usages that may not appear to work exactly in accordance with the rules).