Well well well,
with debate on what a church should call itself, this guy has an interesting concept!

WHY SCUM?

It doesn't sound like a church name ... on purpose. We really want to connect with people who have no interest in "church" by society's definition. There are plenty of churches for "normal people" and we think we have a unique calling to reach out to our otherwise unreached friends. Our name is integral to that process. Whether outcast by society (e.g., punks, skaters, ravers, homeless people...) or by the church itself, many who come can identify with the name "Scum of the Earth" since they have been previously treated as such.
More important to us, however, the name implies that being people of faith does not mean we are better than anyone else. We know many non-Christians who think Christians are out to cast judgment on them. Our name makes it clear that we aren't about that. We are just aware of our need for God, as Scum of the Earth. Fortunately, God never sees us like that! But the name is humble and we like that. --Chris Baker

To this very hour we go hungry and thirsty, we are in rags, we are brutally treated, we are homeless. We work hard with our own hands. When we are cursed, we bless; when we are persecuted, we endure it; when we are slandered, we answer kindly. Up to this moment we have become the scum of the earth, the refuse of the world. (1 Corinthians 4:11-13)

http://www.scumoftheearth.net/

h/t Tall Skinny Kiwi