There are plenty of people filing individual cases as well alleging liability under product liability law.

The sheer volume of those cases could possibly cause major financial issues for the company even if each one costs only a relatively small amount.

The short, general summary of these cases is that under US consumer protection law, the maker of a product is strictly liable for injuries and damages caused by the defective design of that product. An example in ordinary circumstances is that a farmer who uses an herbicide that contains a toxic chemical, and then later develops cancer as a result of exposure to that chemical, can claim compensation from the manufacturer under product liability law. This is what drove the chemical company Monsanto (maker of Roundup) into bankruptcy facing billions in product liability claims.

So a teenager who uses Facebook and then develops mental disorders as a result of that use, has a personal injury claim against Meta.

Even if each individual case is only worth around $20,000 to $50,000, Facebook has hundreds of millions of users in the US, of which possibly hundreds of thousands of people could have a valid claim under this legal theory. And many people could claim a great deal more in compensation. If a person uses Facebook, becomes addicted, gets depression as a result, and then commits suicide, that is potentially a wrongful death claim worth hundreds of thousands to millions of dollars.

Ambulance chasers to the rescue!