In a filing with the U.S. Securities and Exchange Commission, the company said it recently received a draft complaint from the Federal Trade Commission claiming it violated a consent order by using phone numbers and email addresses, which were provided by users for safety and security purposes to target advertising from 2013 through 2018.
Twitter estimates its loss as a result of a potential fine ranges between $150 million and $250 million.
The company said that the matter remains “unsolved”.
Twitter also warned that a recent, high-profile security breach could negatively effect the company, including causing reputation damage and a loss of trust among users.
Charges related to the breach were filed against three, including two teenagers, people at the end of last month.
A number of public figures, including former President Barack Obama’s, accounts were hacked as a result.