You can set a torrent app to be one way.
You can't stop your IP showing in the swarm which is probably all the spiders look for. Well, short of resorting to Tor or similar, which most private sites block and anyway would be going to silly extremes.
Anyway I think the original statement is wrong. Just plain downloading, even via ftp or usenet where there is no upload component at all, is still [for the moment] illegal. It's called format shifting or something like that. Same as ripping a CD for use on your mp3 player is illegal. Simply owning media in one format [CD, vinyl] doesn't give you permission to own it in another format [digital file]. You have to pay as many times over as the formats you wish to own.
