Purposely sending signals into space is akin to a 5 year old kid calling random people, telling them he is home alone and what his address is.
Yea, I've heard Stephen Hawking among other scientists say that things likely wouldn't go so well with the aliens despite the fact many people would like to believe they would be benevolent.
I think the comparison he made was how did it work out for the Native Americans in North Amercia when the Europeans arrived. Not great.
I, too, am in the Hawking camp. I don't think we really should want to broadcast our existence and location to the entire galaxy. Don't think we're ready for first contact yet, in general, and I'm not convinced that advanced beings would be benevolent. I think it is arrogant presumption and absurdly naive to assume that, simply because an advanced species has developed space travel that it should, de facto, be peaceful.