Demonstrating and petitioning and picketing against companies who have treated people unfairly via loan discrimination would be a good first step in addressing this massive issue. But, the fact of the matter is is that this has to be brought to court and tried until it isn't allowed to happen any longer.
Like any other issue, people who have been discriminated against have every right in the world to protest in whatever way they see fit. If they wish to form a picket line or generate a petition, they should absolutely have the right to do so. Whether it will do any good is another issue.
Yes, forming a picket line and distributing petitions are valid methods for protesting actions that one seems unfair. Loan discrimination has kept people from being able to purchase a home or receive other credit. That keeps people from achieving their dreams and as such is cruel treatment for people who have worked to get solid credit.
I believe that a bank is free to extend a loan to anybody that they wish to, I don't believe that they should feel forced to extend a loan to someone they are not comfortable with so while some people may believe they have been treated unfairly I don't believe protesting against the agencies will do anything.
No, this is not going to do a lot for them at all, and it is just going to make them waste a lot of their time. I think that if you were treated unfairly by a loan then there is not a thing you can do, and just move on.