And again, it's still not well defined in the rules. All we have is a bunch of assumptions that Hacker players have thought up by basically saying "Ooh! Let's try this!", and overly permissive GMs have let them get away with it due to the lack of definition.
If it remains, then it needs to be WELL defined. Something like, perhaps, a -1 penalty to <blah> actions for every three cyber implants, or something like that. Basically something that has an effect, but doesn't give complete unfettered control over the cybered individual like some people seem to think is possible (as evidenced by the thread discussing Technomancers puppeteering people with MbW).
Similarly, Background Count becoming a dice pool penalty equal to the background rating to Spellcasting Tests would be a much cleaner way of handling it than a straight Magic/Force reduction, and Adepts not being affected by Background (explainable by the fact that all their 'magic' is internalized to their bodies) could help out with some of the issues people have with them.