Two senior men walk outside a closed residential community in the Xichen district of Beijing on Feb 24. [Photo by Du Lianyi/Asianewsphoto]

The second wave of building closed communities in modern time happened in the 1990s when real estate developers started building such communities for individuals.

Some believed that these closed communities aimed to separate the newly rich created during the country's economic reform. Most focused on the closed communities, reducing public security cases.