I like the new "copyright notice" on RKO (even if it's not called that and it's probably not even a legally binding one), but if you want to take it a step further, you could implement something similar to what Soundcloud is doing:
https://help.soundcloud.com/hc/en-us/ar ... ve-Commons
That is, at upload time allow the uploader to specify the exact type of copyright license he/she wants to use on a particular track, and then display the appropriate CC icons next to the track on the RKO listing. (And all the same would apply to Remix64.com, of course). For already uploaded tracks, set some blanket limited-use CC copyright.
This
still won't prevent bad actors from stealing and misusing remixes for their own monetary gains, but at least remixers will have some protection on their tracks that have a chance to be used in takedown notices and/or in legal proceedings.
I agree with daXX, with the advent of monetized online publishing this has become a complicated issue since RKO first came online 18+ years ago, but I firmly believe that the responsibility of defending the copyright on your remixes falls on you, the remixer (and on the copyright owners of the original SIDs), not on RKO/Remix64.com.
I always operated under the principle that if something is uploaded on the Internet, it will get copied, period. (Even if it's behind a paywall.) If you don't like that and you're not willing to deal with the legal ramifications of defending your creations, don't upload tracks to RKO (or anywhere else for that matter). From this angle, I totally understand - and fully respect - daXX's decision to withdraw his tracks: you want to have full control over who-where-how gets to listen/download your tracks, and RKO is not a platform to allow that for you. Nor was it meant to be such a platform, and I understand that, too.
I have been enormously appreciative of RKO's role on the remix scene since it came to existence, because prior to RKO it was a giant pain trying to find SID remixes (remember the c64rmx mailing list?...) Even today it's nearly impossible to "find all SID remixes on YouTube/Soundcloud/whatever". RKO is pretty much the only site that I can rely on for this, and if I hear something on YT or elsewhere that is not on RKO, I gently ask the creators to consider uploading their remixes to RKO, too. Otherwise, they will just get lost in all the "noise". Here on RKO+Remix64.com you have an admittedly rather niche, but very dedicated and highly passionate audience who are even willing to give you honest feedback. To me, that's the real strength of this platform.
The way I look at it, RKO is the perfect manifestation of the unspoken demo scene mantra of "create for free, share for free, reuse for free"...
Anyway, I forgot what point I wanted to make with this post, but hopefully there are some hidden inside it.