Remember "these people" are your brothers and not your enemies. Also note that I said "primary", not "only". I also believe that we to a greater or lesser degree do influence the spiritual world that surrounds us through our words. We overcome the enemy through our words, not only using the Word as a Sword, but the word of our testimony. And remember the Roman Centurion who when seeking the healing of his servant said to Jesus "just say the word and it's done" (my paraphrase). There is spiritual power in our words, how much I do not know or even begin to understand. But the power is there none-the-less. I've spoken to storms and seen them change directions. I've rebuked demons and seen people delivered, set free. I hope, trust that some of our brothers and sisters have much more revelation on this than I/we do. And I don't expect them to have perfect understanding of spiritual matters any more than I expect myself to have perfect understanding.
Do we need to fear others cursing us? I don't, because I trust that greater is He that is in me than he that is in the world. As children of the light we need not fear darkness. But those still in darkness are often filled with fear and tremendously influenced by the darkness.
Also note that the scripture that notes that a curse cannot take root where there is opening for it, assumes that a curse can stick if there is room given to it. But I haven't studied this stuff nearly enough to have a strongly formed conviction on it.
Blessings,
Sherman
Reference: wiccancommunity.blogspot.com