Some of the victims of the hack have taken to social media over the last few weeks to detail what's happened to their account, explaining that their profile photos are replaced by random stills from famous movies, such as 'Pirates of the Caribbean', 'Dumber and Dumber To' and 'Wreck-It Ralph'.
They have also had their account names changed and are now unable to log in.
Instagram - which offers advice to people who have fallen victim to hackers through its website - has revealed how it's responded to the situation.
A spokesperson explained: "When we become aware of an account that has been compromised, we shut off access to the account and the people who've been affected are put through a remediation process so they can reset their password and take other necessary steps to secure their accounts."
Meanwhile, Instagram launched IGTV - a feature which allows users to post hour-long video clips - earlier this year.
Now, Instagram users can share video content up to 60 times longer than the previous limit of 60 seconds.
Kevin Systrom - the founder of the photo-sharing website - said: "Video deserves a better home on mobile."