That would prevent insiders and common shareholders from selling their shares, but it would in no way prevent an investment bank from unloading their shares through some sort of intermediary.
Everything outside of that is subject to lockout periods (and in the case of executives they are also vesting on new stock)
Morgan Stanley & Co. Incorporated may, in its sole discretion, release all or some portion of the shares subject to lock-up agreements prior to expiration of the lock-up period.
Related poll: http://www.wepolls.com/r/462580/Is-it-right-for-Wall-Street-...