Another group of ANN threads that hired bumping service just discovered. If anyone has any doubt about what's going on, just look at the screenshot below and the same group of 7 accounts working across at least 6 threads (there are probably more but this was enough to make a point)
On top of writing in same threads, some accounts also have certain similarities when it comes to merit: 2 Member rank accounts used Bordijo and Efarilino got 10 merit each from two merit giveaway threads, [Merit] Hey Newbies! Can You Sign A Message? and [Merit] Hey Bitcoiners! Can You Send Encrypted Messages? which then they used to rank up other at accounts. That's just the tip of the iceberg though as several other accounts that can be connected to this group did the same; they got the merit from those merit giveaway threads and then shared them to their alts.