Stick a couple of hyphens in:
"Gogo said at the time that an additional capability - seemingly the use of CAPTCHA to prevent remote access - was an apparent lone function that was not related to traffic monitoring."
But, even then, it's not particularly clear what real relevance that has unless you know the history already.
Specific certs for Google are, indeed, unnecessary. However, almost anything worth its salt when making an SSL connection KNOWS that it's untrusted... even the screenshot says so, which is why you don't get the proper secure icon. You can fake the cert, you can't fake the chain on someone's device without some serious sleight-of-hand that will get you into real trouble.
And almost all proxies in government departments, workplaces, etc. use the same trick to proxy SSL, but they just put the private signing authority into the local devices so you don't know it's "untrusted".
It's not really that nasty - you know you're being listened to - but it's a little pointless just to filter things that any filter could block if you wanted.
And, to be honest, if it's that much a problem, don't block, just rate-limit clients. That solves the problem all round without this kind of fiddling.