When it was discovered that iOS developers had quietly added a feature to the operating system that throttled processors in older phones with degraded batteries, the public was irate. In fact, people seemed more angry about the slowing down than about the phones that were unexpectedly shutting down which is what prompted the software modification in the first place.

The initial reaction was litigation. It started with five customers filing a class-action lawsuit in California, then New York, then Israel. At last count, at least 30 people were involved in suing Apple for the throttling mess.

A French environmentalist group even filed a criminal complaint against Apple for "planned obsolescence." In France, it is illegal to design a product to fail after a period of time so that it has to be replaced. If found guilty, Apple may have to fork over up to 10 percent of its annual profit in the way of a fine.

Reuters is now reporting that the US Congress might get involved. John Thune, a Republican Senator from South Dakota, has begun looking into the debacle. Thune, who is chairman of the Commerce, Science and Transportation Committee, penned a letter to Apple claiming the company has not been transparent enough in the matter.

Congress would like to know if Apple intends to issue future updates that slow device performance. It is also interested in finding out whether the company has been tracking complaints about performance issues.

Apple has defended the throttling, maintaining that it prevents iPhones from failing when they have a battery that has entered a degraded state. It says this actually prolongs the life of the device and protects the circuitry.

"Lithium-ion batteries become less capable of supplying peak current demands."

"Our goal is to deliver the best experience for customers, which includes overall performance and prolonging the life of users' devices," an Apple spokesperson told TechCrunch last month.

The whole thing has been a PR nightmare for Apple which has dropped the price for battery replacements from $79 to $29. In his letter, Thune asks how Apple arrived at that price point and wonders if the company shouldn't offer a free replacement. He also asks if they plan to provide rebates to those who have paid full price for a new battery.

As a point of fact, when iPhone 6s users began experiencing unexpected shutdowns back in 2015, Apple offered them free battery replacements while engineers figured out what to do about the problem. Those who had already paid were offered a refund.

It will be interesting to see where the congressman's inquiry goes. Apple is expected to respond to the letter by January 23.

Second photo courtesy iFixit