Nasza Klasa Sp. z o.o. (~30%)
|Alexa rank||3,086 (April 2014[update])|
|Type of site||social network|
Launched in November 2006, the service had 13.5 million active users in 2009. NK.pl ranks among the top five Polish social networking portals, behind Google.pl, Onet.pl and Wirtualna Polska, and it attracts more than 50% of Polish Internet users (10% of the traffic comes from abroad).
According to Polish media sources dated August 2014, the number of registered users would be no higher than 7 million. Many former users have switched to American behemoth Facebook. 
It allows users to register with particular schools and graduation years and users are able to keep and maintain personal pages containing personal and education details. NK.pl does not require an invitation to join; however, registration is necessary to browse the service.
Privacy and the law
NK.pl offers a wide variety of privacy settings which try to make the user feel protected by offering updated advice and instructions about their safety on the NK.pl site and portal.
They have a privacy team that works with law enforcement personnel when they find threatening and dangerous posts, activity outside of privacy laws and regulations, and other illegal activity.
NK also works with child care services such as the Foundation of Nobody’s Children, which takes care of the healthy psychological and mental development of children.
On 11 November, 2006, Maciej Popowicz, a student of information technology at the University of Wrocław, along with Paweł Olchawa, Michał Bartoszkiewicz and Łukasz Adziński, launched the website "nasza-klasa.pl". The name refers to the song “Nasza Klasa” by Jacek Kaczmarski.
- "NK.pl Site Info". Alexa Internet. Retrieved 2011-10-02.
- Urszula, Jurgiel. "Social death of social networks". Retrieved 4 April 2013.
- Jan Samołyk. "NK gra z WOŚP!". NK.pl. Retrieved 2011-10-24.
- Malachowski, Andrzej (2009). "Phenomenon of Nasza klasa (Our Class) Polish social network site". Issues in Informing Science & Information Technology. 6: 366.
- Klasa, Nasza. "Polityka Prywatności – Ogólne Standardy Ochrony". Nasza Klasa. Retrieved 4 April 2013.