I got an idea, the Town Council is so rich and this idea can make them richer, why not have a gate near the lift lobby. Only resident of the blk with a pass can enter. If visitor like to enter, they have to call the resident to "open" the gate door from their hse, juz like most condos. Transpasser will be fine.
If, u still see leaflets on the door gates after that, u may write a legal letter to the advertiser that they are transpassing and a fine of let say, $500, have to be paid to the Town Council or legal action will be taken against them.
Then no advertiser wud want to hire these leaflets distributor. They sud do the correct way, get Singpost to do for them and put their leaflets in our letter box, so that easier for us to throw it away.
Those 'orange blocks' near the MRT station already had those gates. Residents who are not staying there still be able to enter because if somebody from inside coming out, the person can just go in without even need to call or with any access card.