I mean that in the nicest way possible, but you do not have the knowledge to operate such a website if that's the questions you are asking.

well it was really fun coding it (no ia btw) so I do wanna keep it up. How do you suggest I protect the service from abuse? File size limit? usage count limit? some kind of OCR that filters bad content and bans users... I dont mind extending the service...

Ask yourself the question "which of those things prevents me from going to jail for hosting CSAM" and the answer becomes pretty obvious.

I fear you are mentally modeling law enforcement as rational people who will just accept any explanation you make, and that model does not correspond to reality.

The other thing you may not realize is that the bad guys aren't just isolated guys in their basement who occasionally poke their heads out and maybe compromise a site every so often. There is a pipeline that operates with commercial efficiency, in all senses of the term, including that they are getting paid. I've seen it more directly with link forwarders; there are people actively and constantly seeking out new link forwarders and exploiting them to send spam. I've seen people put them up as a "hobby learning" project and within single-digit hours they're being used in spamming campaigns. You couldn't have escaped this pipeline's notice no matter what you did but with it being on HN you're certainly going to end up on their radar. By this time tomorrow, best case, maybe in a week, if you look at what is actually being stored on your site you better bring the eyebleach.