I have sent a request before and they have done nothing about it. I do not understand why they think they are the domain police. It is a social networking website, not a website to tell us it's safe or not safe. Even if the domain is unsafe report it to the domain's registers spam/abuse team. They will remove the domain name that is spam/abuse the terms of service within 3 business days or less.
Domain police? I think it is a means of security measure to protect
THEIR servers against excessive flooding of spams and to protect legit members against phishing apps. Members are posting personal information on Facebook, and it is only right for Facebook to protect these members against phising, spam, etc. As a webmaster, you should know that it is hard to block individual addresses manually. In co.cc, you can register multiple domains and spammers can take advantage of that. So each time you block one co.cc subdomain, they can instantly use their other subdomains to spam people on Facebook. So instead of blocking individual subdomains, it is more productive to block a whole domain and enable legit subdomains one by one. But I know you already know that.
My point is that, they're only blocking abusive domains that utilizes Facebook. They're not blocking the domain from using the internet. In analogy, they are not domain police but security guards that prevents spammer from entering Facebook.
I've tried that many times, with no results.
I haven't tried that on making apps, but I've tried it on my blog, it works. At first, Facebook doesn't let me share or even like any content from my blog, it returns an error. After filling up the form and waiting for around 2 weeks, sharing and liking worked on my site.
