Major - P3 The following code results in this error.
db.sellers.find().forEach(function(seller)
{ db.sellers.save(seller); });
uncaught exception: field names cannot start with $ [$db]
I have signed the contributor agreement and issued a pull request for the patch to resolve this issue.
https://github.com/mongodb/mongo/pull/46
It affects versions mongo 1.8 and higher.