I wouldn't really be threatened by it if they did.
I'm not claiming any of this is good or should be encouraged. But as much as I have read the new testament, people who want to go down and bow before idols (demons really) 1 Corinthians 10:20, are not discouraged.
What I mean by this is lost people are placed under no burden by scripture to force them to be saved, force them to live like a Christian, force them to do things they have no desire for, ect. ect. Of course people want to worship satan when they are lost... this is why they are lost.
It's not Christianity to force society to behave morally. Now, we can enforce it where we participate in a governance, or through our own choices. But such enforcement is inferior to the power and the gospel of Jesus Christ, nor is it what Christ commanded his church to do. Christ commanded we make disciples, not rule wordily governments which forever remain corrupted. So while participating in government can be good, it's like a ways down on the list of priorities as a Christian.
And the God we serve, is not afraid to send ministers into satanic temples to minister there. He went into the Jewish synagogues, and Christ stated those Pharisees belonged to their father, the devil. So he is at home going into houses and temples that belong to the devil, and revealing the power of Jesus Christ there.
When I moved into my house, my roommate, I found out, has a bunch of witchcraft items. While it's a sin should she have practiced it at all... and I would never encourage it. I made it clear should she practice witchcraft in our house, it would fail miserably.
And look, I am not going to physically stop her from getting out a Ouija board and trying to talk to demons. I don't have to physically stop her. Should she start doing that, Jesus would tell me, and I would follow Christ through that situation to see redemption and deliverance for the kingdom of God.
And honestly, I think following satan openly is a lot healthier mindset than just being an atheist. Satanists are willing to have spiritual showdowns between Christ and satan, and Christ wins. It's just rare satanists come across someone actually willing to exercise the power of Christ in their life. But atheists? Even if they see miracles, their unbelief is so heavy they wont care. They'll walk in the vanity of their own minds until they find their way into hell.
In hell (sheol), satanism and level headed common sense keep each other company. It's common sense people don't rise from the dead after 3 days, it would just be nonsense really to a level headed person. And that wordily wisdom is satanic, and that person is practicing a religion born from the author of lies, and they'll suffer just like a satanist would in hades.
That people would be open to miracles, is a step forward really. And if you practice satanism, you will end up possessed by devils... it's bad, don't do it. But should someone find themselves in that situation, such as when I did as a Hindu, I called out to Jesus who delivers anyone from demons.