Ask HN: Twilio Spam Control

I would like to hear from anyone who has experience using Twilio for a service which has high SPAM potential. For example: Let's say I want to create an application which lets an event staff manager upload his list of available part-time employees, and then for a given event, will auto-call those folks, sequentially until he has enough people signed up for an upcoming event. Great idea, right? But the potential for some unscrupulous person to turn this into a voice SPAM machine, violating Twilio's TOS and the law, is very high. Maybe the issue could be solved by connecting to a no-call database API, but really Twilio says "no unsolicited calls", so that's not enough. Perhaps the only solution left is to make the price per call high enough to dissuade spammers. I'd love to hear from anyone with direct experience in this area. Thanks!