As noted by The Verge, Twitter retains the right to retain both IP addresses and other location-based data as per its privacy policy. If that data can be matched to an address or phone number, it's something the police can use to investigate -- but there's no guarantee they'll find anything, as the company does not store this data indefinitely.

Still, it's good Twitter is cooperating with this investigation, as this sort of horrible action could become more and more common unless some real legal consequences come along with it. Indeed, Twitter has actually agreed to "expedited relief" in this case, not challenging the order or asking for more evidence from Eichenwald. Whether it'll make a difference remains to be seen -- it's still not clear what data Twitter has and whether or not they can tie it to the individual responsible for the attack.