San Francisco, Dec 11 : US Senator Elizabeth Warren on Monday questioned Apple's move to shut down Beeper, an app that allowed Android users to message iPhone users via iMessage. After Beeper Mini, an iMessage solution for Android, was blocked for users, Apple said last week that it took steps to protect its users 'by blocking techniques that exploit fake credentials in order to gain access to iMessage'. Warren, the Massachusetts Democrat who is an advocate for stricter antitrust laws, asked why Apple would restrict a competitor. 'Green bubble texts are less secure. So why would Apple block a new app allowing Android users to chat with iPhone users on iMessage'? she posted on X. 'Big Tech executives are protecting profits by squashing competitors. Chatting between different platforms should be easy and secure,' the Senator added. The Beeper Mini app allowed a way for users to send blue-bubble iMessages directly from their Android devices. For the past couple of days, the app experienced technical issues when users were unable to send and receive blue bubble messages, reports The Verge. Beeper's team were working to enable its app to continue to operate. 'Work continues to fix the issue causing the Beeper Mini outage. We know how hard this has been for those who loved using Beeper Mini, and we're extremely sorry for the inconvenience. We are feeling good, though, and hope to have good news to share soon,' the team said in a post on X on Sunday. Apple had said in a statement that 'we build our products and services with industry-leading privacy and security technologies designed to give users control of their data and keep personal information safe'. 'We took steps to protect our users by blocking techniques that exploit fake credentials in order to gain access to iMessage,' said a company spokesperson. These techniques posed significant risks to user security and privacy, including the potential for metadata exposure and enabling unwanted messages, spam, and phishing attacks. 'We will continue to make updates in the future to protect our users,' said Apple. /IANS