I haven't tried to use it but what I've read in the comments here you also ask for email address.
Confidential, maybe. Anonymous, unlikely.
I don't log any data other than the date besides what you put in the fields. I also don't connect the email address to the listing, it just goes onto a mailing list.
For now it is confidential, though I'm not sure how to reconcile the idea of an API with confidentiality - even when anonymity is involved. Perhaps I should just change it to 100% anonymous?
Does that message even need to be there? Is anyone concerned with it? Might be be better to put the message at the bottom instead. Those who care will look for a statement like that and others won't be distracted.