Nice service. You should considered a default expiration (a week?) to lighten the load, and an option for multiple downloads (?dl=3) so the first n get a copy or multiple tries if corrupted.
Also, you don't keep logs but what about your cloud provider? What guarantees can you make about them, and what responsibility do programmers have to explain the risks to the public? It seems wrong to say "anonymous and secure" without some qualifiers: you must use https, unencrypted files might be copied by the cloud provider, etc...
Thanks for the helpful feedback. Yes, I think a default expiration is a good idea and will be adding this. Other have asked about the ability for multiple downloads, so I am considering this.
Also, you don't keep logs but what about your cloud provider? What guarantees can you make about them, and what responsibility do programmers have to explain the risks to the public? It seems wrong to say "anonymous and secure" without some qualifiers: you must use https, unencrypted files might be copied by the cloud provider, etc...