Well, some parts the usability team have totally missed to do right. I will give this tip totally for free for Instagram, that seems to lack the knowledge of usability.
If you make users confirm their accounts. Don’t place a link in the mail that ends the account. On top of that don’t make the users not get back their account. It is really bad usability to have an end-the-account-link in a mail that is supposed to be sent to confirm the Instagram account. That is really bad usability. Usually links in mails to confirm accounts are supposed to be clicked on. However clicking the only link in the mail ends the account. The user doesn’t get back the account and has to start a new one.
Many users don’t read the email content if they just had a message on Instagram telling them to confirm the account. They just log in and confirm. When you read it, you might have clicked the link and then it is to late to cancel. So even if there was such a function the link shouldn’t remove the account. It should give you a question if you wanted to remove the account. Doing it as is shows that Instagram has a war against its users, just like Facebook. This is just bad user service, not even giving back the account, when users surely clicked on the wrong link. Instagram is really bad. I have more usability issues on Instagram, that I think are really bad. I thought they had money to employ the best… but I am thinking they haven’t employed the best.