I have similar problems with some of my windows - not my kitchen window, which faces the back yard (my electric meter has a transmitter; the meter reader only has to drive by the house, he doesn't have to enter the yard any more) and there's a 6 foot fence between me and my neighbor - and anyway, he's nice older man whose lot is lower than mine; I rarely see him over the fence unless one of us is one a ladder.
The dining room and living room windows, however, face the street - the dining room window faces a park right across the street and there are people there are the time. I didn't want to cover the window - it's a nice view and it faces south, so it gets nice sun in the winter - but I did want to reduce the visibility and the heat in the summer, so I bought white sheer curtains the length of the curtains that were already there, and hung them on a spring tension rod inside the window frame, the kind that uses a spring and needs no hooks or hardware. From within a few feet of the sheer, I can still see out, but from the sidewalk outside (about 10 feet) or farther away, the inside of the house is an indistinct blur. If I want more light, I can open the sheers; if I want less, I can close the curtains.
I also considered cheesecloth curtains for the same reason - the loose weave lets in light and blocks visibility. There are several types of fabric that would do the same thing, depending on the color, the thickness of the fabric and tightness of the weave.