[discostu]

While there is the slight possibility of an “if you can read this you’re a threat, now we’re going to destroy, sorry” message it’s not actually likely. Anybody trying to decide if we’re a threat can probably figure it out with a couple of observation missions. By the time somebody makes contact they’ll have already made the slaves/ destroy/ allies decision, and if they’re not leading with explosions and stuff they probably like us. Might as well open the mail.

[SunkenCiv]

Our signals have been going out for 125 years; trying to hide them now is pointless, and is secondly a sure sign that we're worried about being seen, or have managed to get destroyed (by other listening aliens, or natural causes, or did it ourselves), and that is bound to attract additional attention.

Besides all that, if an alien civ' has the means to reach us, it's a good bet that we don't have the means to reach them, so we can do exactly zero about it. We'll just have to continue to rely on the kindness of strangers.