One key feature of cars is that they can accelerate at high speeds, but only when the owner wants them to. Now, enough Tesla owners have complained about random, unintended acceleration that a federal agency is looking into it.

The National Highway Transportation Safety Administration opened an investigation of sorts into the matter on Monday. It's based on a petition for investigation, which cited 127 different customer complaints about sudden unintended acceleration in Teslas Model S, X, and 3 manufactured between 2013 and 2019.

CNBC reported that the petition was filed by an investor named Brian Sparks, who was inspired after hearing about one incident in which sudden acceleration resulted in a four-vehicle crash. Those 127 complaints involved 123 different vehicles, with the alleged sudden acceleration resulting in 52 injuries from 110 crashes. The NHTSA will open a real, formal investigation into the matter if it decides it's necessary.

Mathematically speaking, it might be tough for the NHTSA to prove this is a widespread epidemic. You don't have to look far in the agency's complaints database to find acceleration accusations against Tesla models, but about 500,000 cars fit into the scope of the petition's requested investigation. Obviously, 123 defective vehicles is only a fraction of that number.

The NHTSA also gave high safety ratings to some of the Tesla models in question. The agnecy investigated car manufacturers for similar issues in the past, including Toyota a decade ago. After an investigation carried out in cooperation with NASA, the two agencies found that pedal misapplication, rather than mechanical defects, could explain many instances of sudden acceleration.

In other words, the drivers were apparently to blame, even if they didn't know it. Whether or not that explains the Tesla issues remains to be seen. If this turns out to be Tesla's fault on a wide scale, the NHTSA has the authority to issue recalls. That would probably not please Elon Musk.