So you make a new account just to ask this?
I can't even open blockchain.info right now. Why are you tracking the specific address? This seems odd.
I was browsing blockchain.info when I saw on the front page a transaction with over 3000 bitcoins, it got my attention.
Basically it's very likely to be Bitcoin's own version of money laundering.
When hackers or anyone who wants their coins less traceable, they can use a mixing service that will send their coins through many stages of mixing for a small fee. Normally 1-3% randomly assigned.
I would not generalize this activity to only people who are up to no good. There are plenty of legitimate reasons why everyday people would want to use a mixer.
Also the 1-3% fees are much closer to under 1% today.