I can’t recall any specific cases of media companies suing online rating agencies like Comscore (NSDQ: SCOR) and Nielsen over traffic numbers, at least not recently (that the general accuracy of traffic rating agencies’ numbers is, well, fuzzy at best, is well known). But now, Spain’s top media company Prisa is suing Nielsen Online over disputed visitor numbers recorded for the website of its flagship El Pais newspaper. Nielsen stats prompted “damage caused by the unjustified downward revision in the number of unique visitors of ElPais.com during the current year”, Prisa’s complaint said, alleging “serious negligence on the part of Nielsen in its measurement of audience figures for El Pais.Com (caused) El Pais and Prisa to suffer serious damages due to lost advertisement this year”. The company says it lost about Euro 1 million (about $1.4 million) in ad revenues this year, because of the allegedly faulty numbers.

Interestingly, the dispute is over how the RSS feed calls to El Pais’ website are made, and how Nielsen was initially over counting the automated calls, and then revised it downwards to only include human calls. El Pais said it checked internally and determined that their RSS feeds/users couldn’t have generated too many faulty requests. The company’s asking for monetary damages in the site. The full lawsuit, embedded below which you can download as a PDF.