Here’s an interesting piece of news that’s sure to reignite debate over consumers’ rights in the digital age: A Boston-based startup called ReDigi has this week launched an eMarketplace that allows users to resell their digital music — as well as buy new and used songs for cheap. (This latter feature will be turned on in the next few weeks.)

While the idea of a secondary resale marketplace for digital content no doubt sounds appealing, given the tumultuous (and lawsuit-heavy) history of the sale and distribution of music on the Web, there are a number of tricky legal issues in play. Namely, with the rise in the digital distribution of music, movies, software, and more, there has come surfeit legal confusion over whether or not the so-called “first sale doctrine” applies to digital transactions.

Basically, under the first-sale doctrine, once the person who owns the rights to, say, a CD sells a copy of that work, the owner relinquishes control of that individual copy. Once that copy is in a new user’s hands, they own it and can do with it as they please, including reselling, lending, or giving it away.

However, Some have claimed that the first-sale doctrine does not apply to digital downloads, for instance, when that digital property has been licensed to the buyer, rather than explicitly sold. In the case of Vernor Vs. Autodesk, the software corporation sued Timothy Vernor (an online software reseller) for reselling its software on eBay, saying that, under the terms of use, the software had been licensed to him, not sold; thus, they claimed that he did not own the right to the software and could not lawfully resell their product.

In 2008, the Washington District Court sided with Vernor, ruling that the software was in fact sold, upholding Vernor’s right to resale. However, that decision was subsequently overturned in September 2010 by the 9th U.S. Circuit