First off, if the Street Sam doesn't know NOT to link his 'ware up his commlink, it's going to be set-up that way. It makes it easier for the Mega's and KE to shut down the cybered trolls. So, it's sold and installed that way. Only makes sense. Secondly, cyberlimbs are computerized. There is a controlling computer in there, as simple as it may be. If a hacker gets into your cyberlimbs, they can make those limbs do ANYTHING within normal operational parameters. It's in Unwired if you don't believe me. Page 102. RAW, pure RAW. In fact, it uses taking over cyberlimbs as an example.
As for making them all look foolish, you point out that if you were a security hacker in a corp, you would have been able to end them all by now. Better to know, and have you fix their crap, than getting dusted by the Megas. Those that don't see it that way, well, the hacker already has access to their cyberlimbs. Let 'em take a long walk off a short pier.