if you publish something online, you should NOT expect *all* people to ask for the permission to use that
Using that logic you should also expect your car to be occasionally stolen when parked in a public parking lot. At a minimum, expect the stereo to be stolen from the car.
Sorry, I do expect normal sane rational moral people to ask permission. However, I don't expect immoral scumbags to ask permission any more than I expect them to ask if it's OK to steal my car, graffiti my garage door, or pet my cat against the grain of his hair as he really hates that.
The problem is that companies like Pinterest, by simply supplying the "Pin It" buttons that go in the browser, mislead normal sane rational moral people to think what they're doing is OK and has been blessed and approved by the webmaster of whatever site they're pinning otherwise they wouldn't be able to "Pin It", right?
Then again, millions used Napster knowing full well it was wrong.