I don't like any protestors who would jump in someones face or get to much into anothers personal space.
If a protestor really wants to reach the heart, they should do so with a calm , cool, and collected manner. Remember JW's think we are the devil, so if we act hostile it will only make them turn away. A calm spirt and a smile, gentle eye contact and a message board with a simple question, not an insulting statement , might put a seed of doubt in their minds.
Trying to hand out leaflets at assemblies or conventions, would probably not be accepted, especailly in front of all the other JW's ,,,, that is why if you were to protest, a sign would get the persons eye and not commit them to talking to an apostate or taking apostate literature. The eye, will keep the message it has seen on the posterboard and remember it for later . And no one would know . I think this would be most useful for those who are out there who already have doubts. THey just need to be lead to the right place. Like this site or silentlambs. A question about the UN involment, Russell's pyramid, many simple things , just pick one, and don't overwhelm them.
That is all it took for me, just one thing to search on my own and I found so many other things once I opened that door.