Earlier quoted context omitted.
I've never understood such assumptions of intelligence. "If a civilization could do X, they could also do Y and Z." Says who? It's not like we're experts in alien intelligence. How can we be, when we have never encountered one?
All true, but applying common sense still has a point. For example, do we want to broadcast the fact of our own existence across interstellar distances? This is actually an active debate topic among those who think about stuff like this. Ironically, after a brief spell of broadcasting our existence with powerful radio and radar waves, we're gradually shutting down the big transmitters for reasons of economy and effic…
We are already doing it(http://en.wikipedia.org/wiki/Arecibo_message). We are also sent a probe with heck lot of details on it(http://en.wikipedia.org/wiki/Voyager_Golden_Record).
>>This is actually an active debate topic among those who think about stuff like this.
True, but we have always been sending radio signals in space and probably will continue to.