The US Securities and Exchange Commission has published a long report on the The DAO that contains an an analysis of the application of US securities laws to token sales/ICOs.

Surprisingly, they decided not to proceed with an enforcement action against anyone involved in The DAO. The full report can be read here: https://www.sec.gov/litigation/investreport/34-81207.pdf.

From the introduction:

The United States Securities and Exchange Commission’s (“Commission”) Division of Enforcement (“Division”) has investigated whether The DAO, an unincorporated organization; Slock.it UG (“Slock.it”), a German corporation; Slock.it’s co-founders; and intermediaries may have violated the federal securities laws. The Commission has determined not to pursue an enforcement action in this matter based on the conduct and activities known to the Commission at this time.