accounts were suspended last week, but now the anonymous creator (or creators) tell us that they're not giving up. "We are preparing our response to Twitter in defense of our legitimacy," they wrote to us in an email, adding, "we expect our accounts to be reinstated shortly. We will succeed."
As for the goal behind the accounts, the creator tells us, "Our recent web presence is to take over the world."
Edit: It's still unclear who exactly is behind the accounts. In their email to us, "cappyvassar" signed the name of a 2010 alumnus. We spoke to the recent graduate, however, and he denies any involvement, so it seems that the person behind the accounts is still impersonating others.