We experienced a technical glitch with the NNTP newsgroup synchronization, and the duplicate posts by "Anonymous" was a side effect when the synchronization problem was addressed on Friday, August 17th. The NNTP synchronization allows posts made in the Developer Exchange to automatically be posted in the NNTP newsgroups, and vice versa.
The duplicate posts appear to only affect the Developer Exchange, and they will be removed from the system shortly.
Thanks for noticing the issue!
Best Regards,
Wilbur Shen
National Instruments