Speaking at the announcement of the Wikimedia Foundation's first ever transparency report in London, Wikipedia founder Jimmy Wales said the public had the "right to remember".
The Foundation's chief executive, Lila Tretikov, called the European Court of Justice ruling "a direct threat to our mission". The encyclopedia is free to view and edit by anyone, and has the aim of building the "sum of all human knowledge".
Following a court case in Spain between a man and Google over web links to a newspaper article about a real estate auction connected to his debt, the European Court of Justice implemented the "right to be forgotten". Since then Google has created an online form where individuals can ask for links in search results related to them to be removed.
Ms Tretikov said: "Our Transparency Report explains how we fight and defend against that. We oppose censorship. Recently, however, a new threat has emerged - the removal of links from search results following the recent judgment from the European Court of Justice regarding the right to be forgotten.
"This right that people may demand to have truthful information about themselves selectively removed from the published public record or at least make it more difficult to find. This ruling, unfortunately, has compromised the public's right to information and freedom of expression."
Google has already received more than 91,000 removal requests since the ruling came into effect, and as of July 18, 50 of those requests related to Wikipedia content.
"Links, including those to Wikipedia may now be quietly, silently deleted with no transparency, no notice, no judicial review and no appeals process. We find this type of compelled censorship unacceptable. But we find the lack of disclosure unforgivable," said Ms Tretikov.