Вот (BSD 6.1)

[[email protected] /]# uname -a
FreeBSD xn02.xxx.net 6.1-RELEASE FreeBSD 6.1-RELEASE #0:
[[email protected]  /]# grep -Ri fuck /usr/src/* | wc -l
8

вот (SlackWare)

[[email protected] ~]# uname -a
Linux raid01 2.6.13 #1 Tue Sep 6 17:56:37 PDT 2005 i686 GNU/Linux
[[email protected] ~]# grep -Ri fuck /usr/src/* | wc -l
86

и вот (OpenSuse)

[[email protected] ~] uname -a
Linux jeffer 2.6.18.2-34-default #1 SMP Mon Nov 27 11:46:27 UTC 2006 i686 GNU/Linux
[[email protected] ~] grep -Ri fuck /usr/src/* | wc -l
0