If you mean voodoo (posses ion, medicine) they don't like you so they're messing it up on purpose, you're not doing it right, it doesn't work on anybody, or it doesn't affect anyone but the natives. And please, word your question better.
I can't answer your question, but it's funny that a black American would criticize Santeria, Ifa or Vodun, when it's quite possible that our ancestors practiced this very faith...
It has a lot to do with sociology. If you think something then bad will happen and if believe it to be true then it will happen. On the other hand if you think positively then opposite will occur.
Oh boy are you in trouble! Don't you realize that witchcraft is a tool of Satan? God specifically condoms this in the book of Deuteronomy in the Old Testament. He describes witchcraft as a sin. Go to the Bible and read it
for yourself. It's in there. Your answer is in your
question - it's all a cover up & its sin. The people of God
are protected the the blood of the Lamb, Jesus Christ, and thought the power of the Holy Spirit. In the name of Jesus
you can cast out the demons of witchcraft! Please! do not
go down this road! Go to God's word and learn. You'll never be sorry! Take care!