Us lawmakers have called on the Justice Department to investigate Apple's monopoly behavior after it was blocked by Beeper Mini.

CTOnews.com, December 18 (Xinhua)-- earlier this month, an app called Beeper Mini came out, which allows Android users to use iMessage services without providing Apple ID credentials. Just a few days later, however, Apple took steps to block Beeper Mini and said it would continue to crack down on similar services.

Four US senators have signed a letter to the Justice Department on Apple's blocking of Beeper Mini, asking "to investigate whether Apple's anti-competitive behavior violates the antitrust law."

It is worth mentioning that US Senator Elizabeth Warren also noticed this a few days ago when she questioned Apple on social media why it was "blocking a new app that allows Android users to chat with iPhone users through iMessage". She believes that this is another example of technology companies "attacking competitors in order to protect profits".

Yesterday, Beeper Mini posted on Reddit that about 60 per cent of users were unable to send and receive messages.

CTOnews.com noted that Apple is currently facing antitrust investigations over a series of issues such as App Store, and whether the company's decision to crack down on Beeper Mini will exacerbate the situation remains to be seen, but the speed with which lawmakers are involved is surprising.

Related readings:

"Android version of Beeper Mini on shelves: native implementation of iMessage protocol, blue bubble chat experience"

Beeper Mini waged a tug-of-war with Apple, repeatedly banned and revived again.

"Apple responds to blocking Beeper Mini: protecting users' iMessage Privacy and Security"