Legal Question in Real Estate Law in California

Contact them to see what they claim is their right to have the box there. I would be surprised if they did not get the permission of the homeowner when they installed it; if they did, you are stuck with that as the box was clearly visible when you bought the house so the prior owner did not have to reveal that.

If the cable box is for your television, you can probably have the remove it, but be prepared to go without cable television. If it is for others, the company most likely has an easement to have it place there. You can probably find this out by referring to the policy of title insurance you were issued when you purchased the property.