How can I protect my images from beeing hotlinked?

[Adult Traffic]

Yes, that's fine OR you can redirect the hotlinkers to somewhere useful.

I just use hotlink protection on a lot of my domains, some I redirect like this one:

###HOTLINKING BEGIN
RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://thissite.com.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.thissite.com.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://thissite.com:80.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.thissite.com:80.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://othersite.com.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.othersite.com.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://othersite.com:80.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://www.othersite.com:80.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://1.2.345.678.9.*$ [NC]
RewriteRule .*[Jj][Pp][Gg]$|.*[Gg][Ii][Ff]$ http://www.someplacetoredirect404.co...MOVE/NO_NO.gif
###HOTLINKING END