An interesting event occoured with the release of Iron Man on Blu-Ray; Blu-Ray players allow people to connect, using a service called BD-Live, to download extra content and the like.  However it would appear that the technical side of this service was not yet ready for a big surge in demand;

Following the release of the blu-ray version of Iron Man on october 1st, Paramount’s BD-Live servers were brought down completely by the popularity of the disc....According to most sources, the content is downloaded as soon as a disc is first inserted into the player. Because of the popularity of this release, Paramount’s servers were completely overwhelmed with traffic....That alone wouldn’t have been a problem, but because this caused the loading of the movie to halt while the content was downloaded lots of people thought the disc itself was defective.