Ask HN: Anyone ever get a cease and desist while using Google Maps?

I have a customer who wants to use Google maps on a site for their customers to know where a shipment is. I think the use skirts the hairy edge of the acceptable use for the free API because the site would be freely available to anyone - but the only people who would care are people using my customer's service. I tried contacting Google Premier API sales a couple of times and get no response. If Google won't even get back to me about a potential $10,000 sale, what are the chances they will notice and ask me to stop using their map API?