Yea realistically a terrorist has so many ways to induce panic or inflict damage it's impossible to simply take things that terrorists can use off the market. An rc car with a bomb is just as easy, as well as ten thousand other things cars, bikes, moped, anything that can move can be controlled remotely and these people have no problem blowing theirselves up for the cause any way it goes. No restrictions or regulations going to stop stupid, ignorant, or evil people from using them the wrong way. The restrictions are only an issue to those who actually are following recommendations or laws and the rest will always find another way.
Wel see soon enough how this all plays out but I just hope all these ads and stories to scare the public don't ruin such a great hobby and such useful technology.
Terrorists will always adapt and find another way so ruining things that we all will use and love is not the answer, that's just a win for them since their main goal is to spread fear and affect our way of life.