The Lord did destroy Sodom and Gomora for the evils they let take control of their lives. But to answer your question, we are not here to "picket". We are not here to judge one another but to let God be the judge. Back in the Old Testament, the Lord often had Israel destroy heathen nations, but that is not what He has told Christians to do.
And as for some people and so called Christians who do rather "picket" others' evils, they are wrong. Hopefully they will come to realize that they are taking the wrong approach.