How to register an Interceptor for all busses?

[Frizz]

I understood that I can register an interceptor like this:

<beans ...>

    <bean id="outInterceptor" class="myInterceptor"/>
    <cxf:bus>
        <cxf:outInterceptors>
            <ref bean="outInterceptor"/>
        </cxf:outInterceptors>
    </cxf:bus>
</beans>

I have a Karaf container that hosts a number of Web Services, each has it's
own CXF bus. Now I'd like to activate my Interceptor for all those Web
Services. How can I do this? How can I activate the interceptor for all
busses?