People HAD already bought properties there before all the banners/warning propped up. And PPP/MQM has been doing this for decades, an encroacher with long reach and contacts encroaches upon state land and builds apartments/flats which are legalized and leased to common middle/lower-middle class who buy after ensuring that the property is leased. And it is NOT their responsibility to check whether the construction is legal or not, it is the responsibility of the state to ensure that illegal buildings are NOT constructed as opposed to allowing construction, buying, leasing, occupation etc.