So basically, you spammed 42k users, and tricked them into sending what they thought were ephemeral pictures but were instead permanently saved and displayed publicly on your website. And now you're bragging about it.
You know exactly what you're being called out on.
I hate to say this because I genuinely like the idea... but this website seems shady to me. They are bragging about reverse engineering an API, and IMO, at best, spamming users with a 10 sec disclaimer saying their photo will be posted online.
Overall: Nice site. Congrats on the technical side. But I really don't think I can condone this.
I'd assume you meant it would be posted online and then removed shortly after.