In some parts of the country, a "house church" is nothing more than a financial racket in which a "pastor" buys a house, lives in it with his family, and has weekly prayer meetings. That's all legitimate, but in many places these properties are exempt from property taxes.
A house church is where the government calls the members cultists, tax evaders, homeschoolers, gun nuts, and child abusers. Then the government calls the house a "compound" which they proceed to attack, surround, and burn to the ground, killing almost everyone inside. Hmmmm....sound familiar?