INAL but usually the data, or at least some portion of it, is owned by the users and the service's TOS and Privacy Policy will state how the service is allowed

INAL but usually the data, or at least some portion of it, is owned by the users and the service's TOS and Privacy Policy will state how the service is allowed to use it. So they have a responsibility to keep their users' data protected to the degree specified in those policies. But really, the data is usually the service's biggest asset when it comes to creating an advertising business which is maybe the biggest reason they want to protect it. But data aside, the company owns the servers you are sending requests to in order to get the data. So that opens another angle for them to litigate. This is where things like robots.txt comes in which I don't think has ever fully played out in court. Yet another angle to go after folks on is the use of trademarks in any marketing copy. It's hard to sell Instagram bots and scrapers if you can't use the word Instagram. I don't even really think a lawyer would have a clear cut answer without going to court but the cease and desist is usually enough to scare people into shutting down. MassPlanner was a pretty widely used piece of software so you'd have to imagine it was making at least a decent amount of money. Not crazy venture backed business money but definitely lifestyle business money if not more. And FB owned Instagram seemingly got them to close up shop without going to court. Even more interesting is that MassPlanner wasn't SaaS. It was desktop software. So MassPlanner wasn't even running servers that were accessing any of the social networks. On the other hand, sites like SocialBlade and tools like Scrapebox have been around for years. So who knows? Ultimately, if you're just an individual scraping for research purposes or maybe you run a social media consulting firm and you're doing it for a client, if you don't publicize it like crazy then you're fine. But just from watching things like this over the years I've noticed most services like this eventually get shutdown if they get really popular. Scrapers tend to fare better than bots but if you get on their radar and they don't like what you're doing you're up against some deep pockets.