Earlier quoted context omitted.
Eh, if I am a majority shareholder then I will read the riot act to the company I hold a majority in after they lose $171M on shitty security. Also, http://www.sony.com/SCA/who-we-are/our-businesses.shtml lists all these so there is some cohesion. AFAIK there's no such Virgin supercompany.
Richard Branson is Virgin's sole-proprietor supercompany. :) But yes, that's true—the investors would be mad at SCE. But would that, in turn, make them think of pulling aside SPE to give them the same talk? SPE isn't even doing anything involving running a public-facing web service; why would the investors presume they'd be at risk? It'd be like YCombinator calling in all their current batch of startups to give them…
If they "screw up" was criminally negligent and had a cost of the order of $100s of millions I could certainly see YC doing that, couldn't you?