The most worrying part is in theory you can do 'anything' to a robot as they don't provide feedback - so any fantasy that you can't do unpunished IRL you can do to a doll or robot... But then... the real think will always be the ultimate dream come true - and maybe these robots only cheers some people on to go after that 'real thing' - which isn't something we'd want.

But then again, they can also be used therapeutically - what if a person that would otherwise molest a person now feels 'just enough' sexually satisfied so they don't molest anymore?

There's two sides to this one and I don't know which one is more true.