We did some digging and just found out ... in Louisiana property damage that exceeds $500 triggers a felony arrest.

You'll recall, Brand allegedly snatched a photog's iPhone Monday night and hurled it through a plate glass window. The iPhone alone costs more than $500.

Here's the irony ... Russell tweeted a few days ago, "Since Steve Jobs died I cannot bear to see anyone use an iPhone irreverently, what I did was a tribute to his memory."

Steve Jobs famously believed he could charge a lot for the iPhone -- and did. And now Russell is paying dearly for it.

The felony -- simple criminal damage -- is punishable by a maximum of 2 years in prison.