thanks for the correction! I had a minus ("-") in my sort order!
db.getCollection('Accounts')
.find({"reputation": {"$lte" : -6000000000000 }},
{"_id":0, "account":1, "reputation":1, "created":1, "last_post":1, "post_count":1, "posting_rewards":1 })
.sort({"reputation":1})