Why not stop by and strike up a friendship of sorts with them? Let them know that you do horses too and that you're excited to see other horsey people in the neighborhood. Commiserate about the high prices of grain and hay, and see how they react. If they agree and talk about hay and grain, etc., then you know they are doing something and you can start to talk about how getting rid of horses is going to be the only option for a lot of people, etc. (Basically, feel them out.) If they say "high cost of hay...I don't need no hay," you can act surprised and say 'what are the horses eating...the average horse needs x pounds of forage a day, and a nursing mare needs x...I'm surprised you're not feeding hay." Essentially start a conversation with them. Maybe they are in over their heads, but if you stop by and act friendly, it might help them learn more. And at least you'll know exactly what is or isn't going on which will help you build your case!