Personally, I think that anyone who wishes to download content from an NG artist of any kind should:
1: Be a registered user, and
2: Have to vote first before downloading.
That way it's those who put in the effort to be apart of the community get the right to download what they like, and to have to vote before downloading helps the artist out as it shows the appreciation of those who like it enough to download.
Voting really isnt hard, but it's also easy to ignore, so if one has to vote before downloading it for themselves it makes sense to ask them to vote as well.
After all, it's not hard...