How do you deal with some one that comes in and fishes to close to you and your spot ?

I was all by myself not a boat in sight and out of now where a boat comes from clear across the lake to with in 20 yards ( to close for me ) and tries to anchor.

What do people think some times.....I guess I'm just not rude enough......I mean its a big lake....go find your own spot......don't come anchor on top of me and ask me if the fish are biting.....

Needless to say I vented on them a little.....but they didn't get the hint and only moved a little.

I felt bad afterwards but really......