Maybe also related, I've also found Instagram to be the easiest service to create extra accounts on. Facebook, Google, Twitter, etc all demand phone numbers to create an account, if not immediately than within minutes of opening. They're all set up to make it as hard as possible to use any kind of fake phone number. And all quick on the trigger to ban new accounts if anything looks the least bit odd, or require even more elaborate confirmation and security.

Instagram meanwhile seems to be, just give it an email on any service and a password, and poof you've got a new account. Post away with anything you want, follow and DM anyone, and no bans, locks, or requests for more info. Maybe they'll lock you out if you misbehave enough, but it seems to be actually hard to hit any limits like that without actually doing something they don't like.