when you're a shareholder of a company which commits an illegal act, you're not responsible (limited liability or something?) - why would it be any different with DAO?
Second: it's not a company: it's a partnership, by my interpretation. By law (in all countries I know of) partnerships by default do not have limited liability. If you want limited liability, you're going to need to set up a proper corporation/LLP, file the proper paperwork, adhere to various laws, keep books, etc. Otherwise, in the US you are probably jointly and severally liable.[1]
The defense "The DAO did it" wouldn't work, since people are voluntary members of the DAO, and presumably voted/stayed in when it got to the point of criminal acts.
The legal system is not a machine you can bypass with magical internet code. (As opposed to a legal system as a Smart Contract running on Ethereum, perhaps.)
[0] https://en.wikipedia.org/wiki/Piercing_the_corporate_veil
http://techcrunch.com/2016/05/16/the-tao-of-the-dao-or-how-t... https://news.ycombinator.com/item?id=11706669