Securing Your Powerline Network
If you don't want your neighbors to potentially pop onto your network, you'll want to install the encryption software that comes with every Powerline adapter. Encryption protects your network by wrapping up all your traveling data into a package, and only you and the Powerline hardware have the key to unlock it.
Note
Without encryption, a neighbor or another tenant in your apartment building could plug a Powerline adapter into one of their own electrical outlets and be able to see everything on your network. A Powerline signal can travel more than 1,500 feet over electrical lines before becoming unusable, so people living in apartment complexes, townhouse condo communities, and neighborhoods where single family homes are shoved up against each other are particularly at risk for signal leakage.