Firstly, that is indeed Kate Moss dressed as Cara Delevingne. Will address that in a bit more detail after the pressing matter regarding Rita's Twitter being hacked is thoroughly investigated.

Have you ever posted a tweet, hoping your followers will get behind you and it doesn't quite take off? Me neither (on account of having a paltry amount of followers - esteemed as they are). If that ever did happen, would you then delete the tweet and claim your account was hacked? Me neither. You'd just say nothing, wouldn't you. People would forget if you didn't protest too much...

According to Buzzfeed, the following tweet was posted on Rita's wall, only to be deleted after it got 2,000 retweets (not to be sniffed at - although you may be a bit miffed if you had in the region of 3.9million followers).

After the tweet was deleted, Rita unfortunately felt compelled to post the following...

It's OK guys! She caught "the hacker" really quickly - like they were right under her nose, using her own hands and so on.

Funnily enough, twitter at large didn't believe her "hacker" claims. Here's some choice responses...
 

Relentless trolling via Twitter didn't hamper Rita's Halloween fun, what with her posting pics of Nick Grimshaw dressed up as her, and what not. We're not sure what Rita went as herself. If Chris Rock were typing this, he'd probably roar "SL*TTY PRINCESS BARBIE!"