A pro-Beijing lawmaker in Hong Kong has called for a "clean-up day" to be held on Sept 21, urging supporters to dismantle anti-government graffiti walls across the city. Legislator Junius Ho has called for 77 of the so-called "Lennon Walls" -- large mosaics of Post-it notes calling for political reforms in Hong Kong -- to be cleaned up. However, there are concerns that dismantling the "Lennon Walls" could be another flashpoint, as Hong Kong braces for a 16th weekend of protests.