Keith Paul Bishop raises that interesting question:
The California General Corporation Law doesn’t define the word “money” but it does include a prohibition on its issuance. Section 107 prohibits any corporation, flexible purpose corporation, association or individual from issuing or putting in circulation, as money, anything but the lawful money of the United States. This prohibition apparently traces its roots to Article XII, Section 5 of the 1879 California Constitution. (Article XII of the 1879 Constitution contained numerous provisions with respect to corporations. In 1930, the voters approved the removal of several of these detailed provisions from the constitution and the following year they were included in California’s first general corporation law.) I’d be very surprised if the draftsmen of this prohibition had dipt so far into the future so as to see the advent of virtual currencies.
Delaware General Corporation Law sec 126(a) contains a similar proscription: "No corporation organized under this chapter shall possess the power of issuing bills, notes, or other evidences of debt for circulation as money ...." Yet more legal problems for Bitcoin and its ilk.