On the other hand, SoundCloud’s API had no rate-limiting mechanism for some endpoints such as /me/following and /me/followers . This means that an attacker could have followed or unfollowed any number of users in a very short time frame. The impact would be similar to the one described above: server overload due to too many requests per unit of time.

tl;dr: SoundCloud’s API was vulnerable to DoS attacks. Again
https://t.co/h3KDbqEG59