Jays are related to crows and yes they do raid nests. We get tons of them but I have quite a few feeders and some are different shapes so there are always places for the little guys.
I love feeding the birds and watching them. It is neat how they come in shifts, some birds early, other birds later, some at dawn or dusk only. There is no doubt Jays are aggressive and bold.
Good luck!
NOTE: For years I got my bird seed for free, loads of it. Now this year I am going to have to start paying for it and I'm dreading it. We will cut back on the number of feeders but even so it's going to be a discipline compared to what we are used to.
Thomas, sent you a PM with the stuck in pond thread link in it..