Not surprising at all. Yelp, Paypal and their ilk deserve all of their earned derision for, amazingly, being simultaneously user, customer, and developer hostile.

Related to the earlier "old & grumpy" 3rd party API post, I've seen far too many, otherwise, outstanding businesses held hostage and summarily executed by either sudden un-explained usage-tier/throttling policies without economic recompense or the outright deactivation of API keys w/o notice or explanation.

Yelp is a scumbag company, I'm surprised it's still in business as it's reviled by business owners and TripAdvisor crushes it in its segment.