This seems a bit silly. Why is this made public? If this was a private conversation then they could set a trap. Now whoever is making these transactions will simply stop and wait for a new opportunity.
That's not the question... the question was why put this on pastebin and have it posted to HN. If this was communicated in a more private manner, you could have actually done something with the information, such as find the people who are moving these coins.
Now, if there is anything nefarious going on, the parties responsible probably know that others are watching.
