This herder's communication is fairly obvious, due to it looking like a hash. But imagine if he/she were to make the bot commands subversive. For example, he/se twits, "Went to the store" and the bot net nodes know that to be "get an update from serverX."
It wouldn't take a lot to do someting like this, it is essentially a simple word substitution and would make it very difficult to tell that botnet communication was happening. To take it a step further, the herder culd rotate the key words/phrases on a regular basis.
The reason I can see for doing this instead of having it hosted on your ISP account, etc. is that ISP's are getting better about shutting down hosted sites when law enforcement calls. Also, why post your C&C on an ISP known for hosting this type of stuff, when you can fly under the radar on a "legit" site. This method additionally provides availability of a true world class hosted service. Also, if the herder were to setup separate accounts for sections of the net, he could have those accounts follow his main account and post upate resposes.