mongodb/mongo-python-driver — pull request #134 by zewt (2012-06-10 16:32:57+00:00)
Title: Initialize ObjectId._inc to a random value.

This is required to prevent collisions on very large clusters. See
https://groups.google.com/forum/?fromgroups#!topic/mongodb-user/ajgO9wUxbos
for details. Other drivers also initialize this field to a random value.