I think black magic does exist but that these people are working with the Devil is that right?? We should therefore avoid these people at all costs.
As for going to Moulay this that & the other, I think that its ok to go & zorr as they have some religious significance. Pray etc. However, when people start kissing stones etc. & asking Moulay ?£$ to heal/forgive/grant them something, then its shirk. Like Nadia said, we pray to Allah alone.
Dont know if thats right, but thats what I think
