Atari then went the extra step and crushed them and (reports say) covered them in concrete to keep people from going out and recovering cartridges, and putting them on sale, taking away from Atari's sales.
Yup, more info here:
n September 1983, the Alamogordo Daily News of Alamogordo, New Mexico reported in a series of articles, that between 10 and 20[12] semi-trailer truckloads of Atari boxes, cartridges, and systems from an Atari storehouse in El Paso, Texas were crushed and buried at the landfill within the city. It was Atari's first dealings with the landfill, which was chosen because no scavenging was allowed and its garbage was crushed and buried nightly. Atari's stated reason for the burial was that it was changing from Atari 2600 to Atari 5200 games,[13] but this was later contradicted by a worker who claimed that this was not the case.[14] Atari official Bruce Enten stated that Atari was mostly sending broken and returned material to the Alamogordo dump and that it was "by-and-large inoperable stuff."[12]
On September 27, 1983, the news service UPI reported that "people watching the operation said it included cassettes of the popular video games E.T., Pac-Man, Ms. Pac-Man, the consoles used to convey the games to television screens and high-priced personal computers."[15] The news service Knight-Ridder further reported on the looting of the dump on September 28 by local kids, stating "kids in this town of 25,000 began robbing the Atari grave, coming up with cartridges of such games as E.T., Raiders of the Lost Ark, Defender, and Bezerk."[16]
On September 28, 1983, The New York Times reported on the story of Atari's dumping in New Mexico. An Atari representative confirmed the story for the newspaper, stating that the discarded inventory came from Atari's plant in El Paso, which was being closed and converted to a recycling facility.[17] The reports noted that the site was guarded to prevent reporters and the public from affirming the contents. The Times article never suggested any of the specific game titles being destroyed, but subsequent reports have generally linked the story of the dumping to the well-known failure of E.T.[2] Additionally, the headline "City to Atari: 'E.T.' trash go home" in one edition of the Alamogordo News seems to imply some of the cartridges were E.T., but then follows with a humorous interpretation of E.T. meaning "Extra-territorial" and never specifically mentions the game.[12]
Starting on September 29, 1983, a layer of concrete was poured on top of the crushed materials, a rare occurrence in waste disposal. An anonymous workman's stated reason for the concrete was: "There are dead animals down there. We wouldn't want any children to get hurt digging in the dump."[14] Eventually, the city began to protest the large amount of dumping Atari was doing, with one commissioner stating that the area did not want to become "an industrial waste dump for El Paso."[12] The local manager ordered the dumping to be ended shortly afterwards. Due to Atari's unpopular dumping, Alamogordo later passed an Emergency Management Act and created the Emergency Management Task Force to limit the future flexibility of the garbage contractor to secure outside business for the landfill for monetary purposes. Alamogordo's then mayor, Henry Pacelli, commented that, "We do not want to see something like this happen again."[14]
http://en.wikipedia.org/wiki/Atari_dump#Burial