There is only eleven NN.com domain names for sale on Sedo domain marketplace. Seven of them contain number 4 and from the rest of ones Goldnames likes 80.com
Most of them already belong to Chinese users CN, few have US, one TW, and some private WHOIS. Here they are, all eleven NN.com domain names: 27.com 04.com 45.com 47.com 29.com 48.com 62.com 46.com 40.com 43.com 80.com