These look like copies of older user accounts. Possibly created as a result of name changes - to prevent the old name from being hijacked. Never mind, read this:
They should've done that for the name change system as it is/was extremely buggy. I kept having to send pms twice when people changed their username in the hope one got through because the name selection tool on the messaging system was returning a different name (they still replied though so it got through).
