Ah, that was fun.

IRC (Internet Relay Chat) is a type of chat. Most (if not all) groups use it.
Files can be distribute via IRC, too. People set up a bot (server) which holds files and sends them to anyone requesting it via a specific message. This type of transfer is called XDCC (or DCC).

In this case, ACS-Subs's IRC channel is #animecorpx in Rizon, and their bot is [ACX]Releases. For example, I connect to Rizon network, join the channel. I send the bot this message to ask it about episode 19: "!find Final Fantasy Unlimited 19" (without quotes). It responds me: "XDCC SERVER - slots:[49/50], Queue:[0/800], Min:10.0kB/s, Max:5000.0kB/s, Cap:64000.0kB/s - /MSG [ACX]Releases XDCC SEND x - Found: #1371:[ACX]Final_Fantasy_Unlimited_-_15_-_Jane_The_Moving_Ocean_Puzzle_[ALI]_[192A2F40].mkv,233M #1375:[ACX]Final_Fantasy_Unlimited_-_19_-_Ai_Meeting_with_Clear_[ALI]_[BA3C4E3A].mkv,233M"
From that, the message I need to send to tell the bot to send me ep 19 is "XDCC SEND 1375". It sends me the file immedietely after I send it the message. http://i.imgur.com/WLq7wqg.png

Here is a XDCC guide: http://www.anime-sharing.com/forum/sit...dcc-49142/
Oh yeah, you use a phone. There should be some IRC clients for phone, too.