we were browsing through google for some information and we found this conference talk about NetBSD rootkits also the mismanagement of security in NetBSD.
What shocked us most is the fact that NetBSD never bothers to update security software within their pkgsrc tree and thus NetBSD users are left with out-dated and useless anti-virus, firewalls and rootkit detection software. In Linux, this sort of thing is never tolerated and software are constantly patched and updated which just goes to show that Linux is still better then anything BSD can hope to be.
BSD, the truth 
They use lkm, which hasn’t been deprecated as of NetBSD 6. That vulnerability is over 5 years old and still hasn’t been fixed.
LKM ist deprecated since NetBSD 6 and NetBSD default kernel never used lkm. You must compile a special kernel with lkm support.[b0ca9e]
But NetBSD no is a mature stable system as told Andrew Tanembaum to LinuxFr.org? reference:http://linuxfr.org/nodes/88229/comments/1291183