What should I do if I am being threatened on Twitter?

[Olivia]

I was on Twitter yesterday and asked a question about when a TV show episode would be airing to a Twitter account I thought was official and got a threatening response that said that I was fat and ugly and that they would find me and kidnap me, I'm very scared and concerned. What should I do about this.
Drake, I did not put your phone number or address on the internet at all.
SpaceSpace, I did not share my location at all

[Julian]

LOSE YOUR HEAD AND FREAK OUT
oh wait do the opposite and stop worrying.

[Drake B]

if you have not put your phone number or address on the internet, you should not be worried. You can report him on twitter.

[Space Space]

If you have shared your location on the internet, be worried.
If you have not, there is very little chance they will find you.

[Nancy Kay]

Ignore it, just some stupid jerk going for a reaction.

[Dr. Pepper]

Omg. That's serious. First, report this person on Twitter. There is a 1 out of 100,000,000 chance the person will find you. Next, wait to see what Twitter says. The guy will be monitored, and if he does it again or something like that to anyone on Twitter, he'll be kicked off. Youll be fine. Don't share your address or name. Hope this helped and please don't worry! God bless

[Kasper]

Assess the likeliness that the owner of said twitter account will indeed follow up on his/her alleged threats. Are you traceable towards your address by the data provided by your twitter account? If yes, you might want to secure that by deleting said data.
As for the threat itself, in most cases words are just words on the internet and rarely will people actually follow up on their threats, lest there is a very strong reason to do so. Language is very much subject to deflation and inflation on the net, in such a stron notion that meanings of things might very well change.
Every day thousands of death threats are flung across the internet, whereas very few actually get carried out.
As to the threat of kidnapping, that would not help the perpetrator at all, as his/her intention was to hurt you, which he succeeded at, clearly, but kidnapping does not happen with an advance announcement. That is just plain stupid and the person who threatened you knows it. Announcing to someone he will be kidnapped is a great act of stupidity if actually intended, so the only possible outlet would be that this threat was just words, no intention to follow up on anything.