could be because of mediafire's no porn rule...
Nope, emails that I got from MF plainly stated: 'An owner of copyrighted material', 'Complaint', 'Strike', 'Account will be banned after a series of strikes' etc.. And then they've banned it after 5 - 7 strikes.
Noone mentioned any porn rules. First strikes I've received were for non porn pictures of girls from official Manga creators (Absolutely marvelous quality for 'Profile' type of pics), that was 4 or 5 month ago. I removed all of those but about a week ago a whole series of strikes began to come in cause of complaints from Hentai pornsites. They are either buying pictures from Artists OR simply hiring Artists to draw for them and we're using those pics (Some are of really excellent quality.)
There could be other issues, maybe account tipped over 100k downloads or 5TB of traffic and got red-flagged for a thorough check or some sh!t like that... thou I am not sure about Shukuyou. We need a better solution, torrent may be an answer but I doubt it will be sustainable or provide a good speed. Passworded files (Maybe a master password for all files for WM) or different hosting could be a key.