Sellers could be listening or watching to see what your reactions and comments are about their home. Even remarks that you may think are harmless can be used against you.
For instance, if you gush about how much you love the house and can't wait to buy it, that seller will most likely be less inclined to negotiate the price with you, since they know you love it and have to have it.
But what about privacy?
In many ways, when you open your private home to the public, it can be similar to a shopping mall, restaurant, sports arena or any other public space. Allowing the public in can change the dynamics in terms of strength and amount of rights you may or may not have.
Many agents argue that homes that have such devices installed should include a notice or sign indicating that there are recording devices present. Currently, there are no laws that require such notice.
In the meantime, use caution when viewing homes. Sure, you can discuss things with your agent, but be sure to keep them neutral. Leave the serious talk about writing offers or how much you're willing to pay until you are in a place where you know the seller won't be listening.