There is a feature of loud, aggressive, angry protest that might just have the desired impact of that protest group. Some psychological studies have been done that shed light.
If you are part of a group who are interviewed individually about say "Friendship" and are asked a question like "What is the most important thing about friendship to you?" Most people will respond with..."Loyalty". However, if you are provided with a psychological assesment of your personality soon after this interview and the assessor declares that when it comes to friendship, you are poor in "Loyalty", then the participants are re-tested with the same questions a previously asked, those who formerly claimed "loyalty" was most important then...did not report it now!
There's more to it than that, as the video below will show, but essentially, when one group of people express some passionate ideas about something in public, and a very loud angry counter protest group surround them and scream at them, presumably the reason they do this is to diminish the strength of those ideas in the original protesters.
Knowing this, we should not read too much into people who have 'changed their mind' after a period of vocal and aggressive protest against what they stand for.