When you look at the power and money put into avoiding reductions on drugs like alcohol and tobacco, what on earth does anyone think the adult industry is going to do to protect its income streams, given that they have hundreds of millions more in disposable income to thwart any and every attempt to prevent access to their sites?
You might as well hold out a tissue in front of you to stop a bullet - the notion is a farce, and everyone involved will simply ignore it and carry on.