Its interesting to see YC going after such a risky ideas. Perhaps its just a sign of huge cohones, which is good, or maybe just a pure desperation? I mean, they hit jackpot with AirBNB and decided to invested, despite the fact the co-founder was or still is on FBI scamers list  and he ran his scheme off of government servers that you and I had to paid for in tax-dollars.
But aside this, I get the deception here that they don't get pricing directly from Geico, but rather they calculate the price per Geico per State (if that is really true, because what stops them from harvesting the data off of a carrier website anyways and switch algorithm just in case they get subpoena or something - can you see a similar pattern of questionable legality of business practices with AirBNB?).
But the issue remains: what stops Geico from requesting their name to be removed from said website? After all, Geico is a protected trademark, and if Geico can prove that this website was providing incorrect information in regards to their rates, then they can claim that said misleading information is harming their business. To me, its a straightforward quick court case.
Side note: its really sad to think YC would go after such a business idea. Whats next? YC-founded youporn version 2.0??
EDIT: I never treated hackernews as a popularity contest. I always stay behind my word even if it may hurt someones feelings. I knew I will get heavily downvoted (which is fine) since YC is investing into this idea, but perhaps when you do so, maybe you can point out where I am being wrong, instead of just clicking down-arrow. That's kind of covardishy, if you ask me. :)
Trademarks are primarily to protect consumers, not companies. As long as you are referring to Geico, and not trying to name some other company "Geico", you cannot fall afoul of their trademark. The trademark is to make sure that you are referring to the right company, and that's all.