Who knows? As far as I know, not a single mass dowloader worked on emuchina, except blackwidow, but it was so damn slow I could never finished downloading a single ADF from there.
But I don't think Tosec Amiga roms leechers are the ones tho blame, for They are not a very large group, compared to Mame or GBA Fans.
I do believe MAME and GBA roms are the most demanded (and downloaded) ones. If the problem was the leeching, one could do exactly as The Underdogs and Aceroms do... one download allowed (no simultaneous downloading) for each IP.
But this is all nonsense, since the Emuchina guys clearly stated that the problem was their ISP going out of business, and nothing else:
"There are some trouble we must let everybody know, the server we are hosted on may go out of business (our contact is already untrackable), so if they shut down the server we will be unable to switch it back on, that's why, for now, there are no ROMS download available (besides Arcade/street machine). We can't grant anything but that until the server is up we'll keep providing updates on news and roms"