The Cambridge Analytica data-privacy scandal that saw Facebook Inc.’s (FB) stock get hammered and put the company’s CEO and founder Mark Zuckerberg in the hot seat in front of Congress has also had some damaging repercussions for videogame publishers. Following the scandal, Facebook made changes to its Login software that apparently had had a negative effect on second-quarter performance for popular “Candy Crush” game-publisher Activision Blizzard Inc. (ATVI), and for Zynga Inc. (ZNGA), known for games like “Words With Friends,” according to MarketWatch. Both companies saw their stocks decline following their earnings reports.

 Stock  YTD Performance
 Facebook  + 4.2%
 Activision Blizzard  + 10.9%
 Zynga  - 1.3%

Facebook Updates

Videogame developers use Facebook’s Login technology to simplify the account set-up process for their own websites or apps, borrowing some of the individual-user data collected by Facebook. That Login technology partly played a role in facilitating the harvesting of data on millions of Facebook’s members by Cambridge Analytica. (To read more, see: Facebook Faces $663K Fine for Cambridge Analytica Data Breach.)

After the scandal surfaced back in March of this year, Facebook implemented changes to the Login technology that restricted access to their users’ data. One of those changes included a requirement that users who had not logged into a developer’s app or website over the past 90 days to re-log-in, a change that appears to be responsible for issues that both Zynga and Activision reported in there recent earnings calls.

Although Facebook was not named specifically by Activision as the culprit for their reduced sales, in an email last Friday, Piper Jaffray analyst Michael Olson indicated that he “just couldn’t think of what else” the company’s issues could be, and that Zynga had come to a similar conclusion about their reduced sales, according to MarketWatch. (To read more, see: Facebook Asks Banks to Share Customer Information.)

Activision

The day following the company’s earnings report on August 2, Activision’s stock tumbled more than 4% as both sales and earnings showed a year over year decline. Revenue and earnings, however, still came in ahead of analysts’ consensus forecasts, and the stock may present a buying opportunity as investors anticipate strong growth over the near term in the global gaming market.

Zynga

While reaching a high of $3.94 on August 1, the day Zynga reported earnings, the stock closed more than 2% lower. While revenues were up year over year, the company reported breakeven earnings, which were below expectations. Zynga also reported average daily active users nearly 14% below analysts’ expectations of 26.7 million, which the company’s CEO Frank Gibeau attributed to the changes Facebook made to their Login technology. The company expects to see stronger bookings in the future driven by some of its newer games like “Merge Dragons.”