SamFisher202 said:
They should fear us, not the other way around. Could there possibly be a crueler, more aggressive species out there than humanity?
Quite easily. It's rather fallacious to assume that humanity is anything special, and that
our moral considerations will be able to have any bearing on a new, entirely unknown species.
In my mind, humanity
as it is will always have more to fear from alien contact than the aliens should. If they're able to traverse interstellar distances simply for the purpose of contacting us, in all likelihood they will be able to exterminate us very easily. If these aliens are anything like SamFisher202 above, they
will most likely kill us. After all, we would be the most cruel, aggressive species in existence, and with that reality in place there's no other solution than extinction or some other form of neutralization.
We, on the other hand, will have virtually no real offensive capability against an alien species capable of (I am assuming relatively easy) interstellar travel for... quite some time, presumably. Which is why aliens have nothing to fear from us: unless there is a psychopath in command, we will be cognizant of the fact that offensive action on our part will never end well.
EDIT: Of course it doesn't mean contact would end poorly for us. Simply that serious caution would have to be taken, and I'm more or less certain that the alien species would be on the same page in that regard, unless of course they are so radically different.