In what sense is the devil bound? In a very major sense, but we not going to run away with the idea that he is totally bound. If we did that, Scripture would contradict Scripture.
When you see what's going on in the world today, and you think we are approaching the end times, and laws are increasingly passed which are going to make the truth illegal, ultimately, and all Christians possibly prosecutable for not recognising the new alternative morality (which is immoral), and ever stating Christian views; when you see that, remember that it can't go all that far, because the dog is on a chain, and Satan is restrained. He cannot, for example – though he strives to do this – organise the whole world against Christ. He can get hold of some nations pretty well, but what he longs to do is have all world governments following the same script, legislating against Christ, bringing force to bear, persecuting and imprisoning. He cannot do it. There’s quite a lot of things the devil cannot do, because he’s chained. He can tempt us to sin; he can tempt us to doubt, and through his demons. He can pollute a church if the church lets him, so it gets so bad that it loses its lampstand and Christ withdraws, but he can't close us all, and he can't wipe us out. Not until the last elect saved person comes into the kingdom and the thousand years, a symbolic period for the gospel age, is ended.