In all fairness... they did not steal your ideas... you gave them your ideas in the form of some screencasts. I understand that when you gave them the screencasts, you were hoping for a different result. But none-the-less... you gave them the screencasts.
That being said, if they did use your screencasts as inspiration for coding some features they had never thought of before then that is pretty slimy of them. But I (and probably you) have no way to know when they started planning those features.
That being said, if they did use your screencasts as inspiration for coding some features they had never thought of before then that is pretty slimy of them. But I (and probably you) have no way to know when they started planning those features.