The Digital Millennium Copyright Act. Its "safe harbor" provision is what draws the line between pirates and legally legitimate Web companies. That line isn't always crystal clear, as the ongoing saga of Grooveshark demonstrates.

Few would call the DMCA perfect, but its attempt at modestly redefining copyright for the digital age has had a major impact on the way the Web works, and in many cases has enabled innovation to flourish. Without it, sites like YouTube might not be what they are today.

When a site is perceived by a copyright owner to run afoul of the DMCA, those rights holders have the option of issuing a takedown request. From there, things can get complicated, or they can be resolved rather quickly. In some cases, legal battles can drag on for years if a site owner and a copyright owner don't see eye to eye.

So how does it all work? Web hosting company Nexcess has seen their fair share of takedown notices and has put together a flowchart explaining how the process typically works. As you can see, it sometimes turns into a cyclical, repetitive affair depending on how the communication between parties pans out.

(Click to enlarge)