I once e-mailed their abuse address when I worked at a web hosting provider. They had a bug in Gmail that made them send the exact same message hundreds of times per second, for days. We know this was a bug because the sender was one of our customers who had sent the e-mail to his own address with us, and now he got thousands of copies of it per minute. Something had apparently ended up in an infinite loop on Google's end.
I obviously contacted the abuse address listed in WHOIS with this rather important message but when I didn't get a response within an hour we had to ban Gmail. Not everybody can say that they made that decision! (Eventually we unlocked everything but his sender address).
Two WEEKS later I got a template reply with totally irrelevant links to their FAQ. I lost all respect for Google then and there. I thought that they would at least know how to be good netizens on the tech level but no.