Any aliens with the technology to raid Earth would have no need to.
But then again, they could have the motives of Democrats or muslims.
That is possible.
Totalitarian mentality probably would not be xenophobic.
The desire to control others totally is an all-consuming desire.
Since we don’t know what they need and what their morality is we are safer not contacting them.
Of course the earth media will be all too willing to lick thir boots...
Seems, to me, like a LOT of unwarranted assuming about a LOT of variables, had to go into that assertion.
Stanton Friedman has an excellent discourse on why that assumption is likely extremely flawed. It may be on his website.
http://www.stantonfriedman.com
As a psychologist and sociologist, I think it's a riot when grand pronouncements are made . . . about ET's . . . and their "MUST BE" psychology, sociology, values, interests, habits etc. I doubt that we know as much as we THINK we know about the psychology and sociology of dogs, sloths, or ants or aardvarks.