I'd like to avoid this as much as possible. Only a fraction of the entries on BotB have been rendered to MP3, making a lot of entries inaccessible to the guest. Frankly, I doubt we'll ever convert them all.
We'd deprive some people of good times (especially those who don't care to go as far as registering), and we'd lose interest from those who just barely wanted to dip their toes in the water.
I have two ideas:
• Have separate download page for guests. They have to specify the entry number and the compo number (not the OHC number for OHCs). While this won't be a challenge for human leechers, it's a nice start.
• Keep things the way they are, but apply the spam counter-measurements you use on your blog. If there are a lot of random downloads coming from certain IP addresses, they can be flagged for an admin to look at. Though, if BotB explodes, this won't work so well.
Sorry for the rushed comment, if you need any clarifications let me know. I've been working on this for, like, 40 minutes with so many distractions. That is too much time. =x