I am not sure about mass killings. Some say that Facebook enabled a genocide in Myanmar, but I think that is a false hypothesis. It was used as a platform by conflicting parties, sure, but it wasn't the reason for the conflict.
Google has strong governmental ties right now, so opposing any of their messages regardless of content seems sensible. Without backlash it would just fortify the situation right now so it has to be costly for both Google and political parties. Google lost a lot of trust in recent years, sadly that is not true for their market influence. Perhaps they put out these message because government contracts require it, the user wouldn't know because that is not transparent.
It's not what I think, it's what has been proven in the 32 years since photoshop was invented. What killings are you talking about that were caused by the existence of image manipulation?
https://www.bbc.com/news/blogs-trending-45449938
> "A SIM card was about $200 [before the changes]," she says. "In 2013, they opened up access to other telecom companies and the SIM cards dropped to $2. Suddenly it became incredibly accessible."
> "People were immediately buying internet accessible smart phones and they wouldn't leave the shop unless the Facebook app had been downloaded onto their phones," Mearns says. Thet Swei Win believes that because the bulk of the population had little prior internet experience, they were especially vulnerable to propaganda and misinformation.
This means that large amounts of people are not internet-savvy enough to spot fakes and know not to trust them.