Today, you rarely see contraband cigarette peddlers at the usual hot spots in Geylang and Sungei Kadut.
Regular enforcement measures as well as the outbreak of Covid-19 have reduced face-to-face dealings between these street vendors and illegal cigarette buyers.
Still, the problem has not been eradicated as trades have simply gone underground just like vice and gambling. Deals are conducted via private chat groups and social media platforms, away from unwanted attention. But such illicit trades do not escape the watchful eye of law enforcement.
On Tuesday, three Chinese nationals were arrested when they had tried to sell part of their loot - 46 cartons and 42 packets of duty-unpaid cigarettes in all - to undercover Singapore Customs officers.
Customs' Suppression and Community Engagement Branch (SCEB) had mounted two operations that day against peddlers who were dealing on WeChat, a popular Chinese messaging app. The media was allowed to observe the night operations in central Singapore.
In the first operation, the SCEB had made earlier arrangements to buy 20 cartons of contraband cigarettes from a peddler near MacPherson Lane. One of the leaders of the SCEB operation told The Straits Times that unlike street peddlers who sell loose packets of cigarettes, online peddlers prefer selling larger quantities.
The officer said: "The only way to lure them out is to make a purchase. But from experience there's no guarantee they will show up."
That night the peddler, who lived at a nearby block, did show up - only to be arrested on the spot by plainclothes Customs officers. In a red plastic bag, he had 15 cigarette cartons wrapped in black tape.
"The peddler we arrested told us he kept more cigarettes at home," said Mr Chua Teck Hui, head of SCEB. "But we found none there."
Initial investigations revealed the peddler's co-tenant had seen the man getting arrested and rushed to their flat to get rid of evidence.
He threw some cigarettes down the rubbish chute, and also stashed a bag containing 17 cartons and 14 packets of illicit cigarettes on the 12th floor of the block.
In the MacPherson Lane operation, where 33 cartons and 32 packets of cigarettes were seized, the total duty and goods and services tax evaded amounted to $3,320.
In a second sting later that night, another peddler was arrested near Jalan Damai in Kaki Bukit.
Twenty-one online peddlers were caught in the first half of this year; 42 were arrested in all, last year.
Some 2.9 million packets of contraband cigarettes were seized from online sellers, street peddlers and smugglers last year - 500,000 packets more than in 2018.
The number of people caught buying duty-unpaid cigarettes last year - 6,920 - was also up from the 6,115 the year before. This figure has trended upwards since 2016, when 5,184 buyers were caught for the offence.
"Singapore Customs will clamp down hard on anyone who uses social media and messaging platforms for any duty-unpaid cigarette activities," said Mr Chua.