Snapchat is introducing new limits for its youngest users - and the official explanation is protection from abuse. But when a social network suddenly grows concerned about children, it's worth asking what's happening in the courtrooms behind the scenes.

Under the new rules, users aged 13 to 15 will only be able to share posts in the Spotlight section with people they follow back. Minors under 16 get a special profile for Stories and Spotlight visible only to friends, with no figures shown such as like counts - exactly the metrics that create pressure to compete for engagement.

Until now, this group could share in Spotlight with everyone, though the posts weren't linked to their profile, which kept strangers from contacting them. Users aged 16 to 18 will still be able to post more widely, but limited to friends, followers and people with mutual acquaintances. Parents, through the so-called Family Center, will see how much time their children spend in particular parts of the app.

The context explains part of this sudden concern. Snap faces a lawsuit this year accusing it of fueling social-media addiction, and it's also fending off similar cases across the US. It's hard to separate the new concern for child safety from the pressure of lawyers and regulators. Instagram acted similarly in recent years, with special accounts for teenagers.

And the reaction from the top shows how much the industry still denies. Snap's CEO, Evan Spiegel, in an interview cited studies to argue that "Snapchat has a positive effect on users because it connects them with friends." Maybe. But the question that stays unanswered is simple - if the platform really is so harmless, why did it take lawsuits to introduce these limits?