It all depends on what I was informed of. Say it was about a past mistake or something that absolutely has nothing to do with now- and it is not who they really are currently than No I would ignore it because it is in the past and honestly none of my business.
If it had something to do with now and my safety or my families'. Than I would have to take steps of caution and act in wisdom not by my emotions.
This too is an area that would vary widely. Like if someone my child was playing with was involved in such bad,dangerous behavior that could harm my child- than my opinion would change and it would no longer be acceptable to continue as it was.
Or if I found out someone was prone to sexual perversion and couldn't be trusted around my children-than that's it all relationship is over-my opinion of you has changed.
We can forgive people and love them but we can not be a fool and just let there bad choices abuse us,or harm our families in any way.
Over all I am pretty forgiving when it comes to people because I too know that I can't even get it right all the time and I too need mercy,love & forgiveness!