my gate is like a rubbish bin

[KJ]

Yeah, I tried calling the people who advertised once. Got the phone slammed down on me.
Does anyone know if this constitutes to littering? If so, then I'd say all HDB estates have a very "serious" littering problem. 

is there any way we can report this to the police?

best way would be to write to the papers...
the respective authorities would somehow reply.

hmm   wonder if there will ever be a new law to state that distributing flyers in such manners would be illegal

[kochmeister]

I think it constitutes to the bulk of litter in most housing estates

[Styliaga]

is the way of life in hdb .....i just take it easy
I just read and throw away into the bin

Cheer up guy

[KJ]

these paper ads wld be useful if we have winter season and a fireplace to keep warm 

then it wld be the more the merrier