The basic premise:

• We're finding useless operations in the db.currentOp() when using replica sets.
• The useless ops are in the secondary nodes.
• The useless ops appear to be tied to "Replica Set Syncing".

Problems:
0. The useless ops exist.
1. The useless ops are "un-killable". However, bouncing mongod seems to make them go away.
2. When a replica does a complete re-sync, the useless op contains a seconds running.

#2 causes issues when watching for long running queries.

Reproduction:

• See attachment
• Reproducing is really as simple as forcing a re-sync on a dead node (stop mongod, delete data, re-start)