Apple seems to be getting more reactions than it expected to its recent iPhone performance apology letter. Now, the higher U.S. agencies have involved in the issue after a number of users filing lawsuits against the iPhone makers. The U.S. Department of Justice and Securities and Exchange Commission are looking into the issue and questioning Apple. Both the Agencies are investigating to know if Apple has violated any of the consumer law by throttling down the iPhone&#39;s performance.On December 28, Apple released an open apology letter for its iPhone users and revealed what it&#39;s been doing for long. In the letter, the Apple discloses that the latest iPhone update that has been deployed by the company, intentionally slowed down the iPhones. According to the tech giant, the dying lithium-ion batteries won&#39;t be able to cope up with the iPhone and could cause a sudden shutdown. In order to help the batteries, the company slowed down the performance of the iPhone without notifying to the users. Apple also shared that it slowed down the iPhone SE, 6, and 7 models. However, as a gesture of apology the company cut down the iPhone battery replacement cost by $50.After the iPhone maker has posted the apology letter, a number of users filed lawsuits against the company for breaking their trust. The U.S agencies are examining the issue and requested the answers from Apple over its disclosure. According to the sources, the chairman of a U.S. Senate committee is monitoring the investigation over the tech company.By now, more than 50 class-action lawsuits have been filed by the consumers asking for the answers from Apple. According to the field legal cases, the consumers blamed the Apple&rsquo;s latest update for downgrading their iPhone&#39;s performance and making it shut down unexpectedly. The consumers also accused the company of tricking them to either by a new iPhone or battery replacement that worth around $80. According to the reports, the most of filed cases are from the federal court in San Jose, California. However, the trial of the cases is still pending and the lawyers representing the consumers are requesting to judges for holding the litigation in California as soon as possible.