As of Friday trading, Equifax (NASDAQ:$EFX) shares have plummeted a gloomy 18%. Cyber security experts and customers have criticized the consumer credit score provider’s response to a hack that may have stolen the personal details of up to 143 million Americans.

The data breach scandal is the largest of its kind to be recorded. The scandal is further dramatized by the severity of the information exposed, which included names, social security numbers, birthdays, addresses, and driver’s license numbers. As a reference, bigger hacks by size, such as those disclosed by Yahoo last year that affected a billion accounts, did not disclose as much sensitive information.

Equifax is now facing two class-action lawsuits, in Portland, Oregon, and Atlanta, Georgia. The basis for the lawsuits are negligence in protecting consumer data. Twitter users also reported that the company’s customer service representatives were either passive or unhelpful when notified of the breach. Some were even unaware that it was happening.

As for Equifax’s response, the company stated on Thursday that the breach was driven by criminals who had exploited a vulnerability in a website application to gain access to certain files.

Cyber security experts criticized Equifax for setting up a support website under equifaxsecurity2017.com, under a different domain than the company’s main website, equifax.com. This practice is susceptible to fraudulent data collection.

Inevitably, the sheer scope of the scandal will drive a number of negative headlines for Equifax that will weight on the brand for the foreseeable future. For now, Equifax will attempt to salvage what is left of its data integrity through continuing investigation with law enforcement agencies and cyber-security firms.

Featured Image: twitter