[6] Joe's brother Brendan was described by him as "crippled, ruined and wrecked by a savage addiction" to sniffing glue which he developed as a teenager.

In October 2008, he was proactive as a supporter of Irish pensioners who marched on Leinster House (home of the Oireachtas) to protest at the proposed means testing of their medical cards in the Government Budget.

[10][11] However, earlier that month, he was reportedly censored by the government when he attempted to continually discuss the effects of the global financial crisis in Ireland.

[12] This followed on from the outrage caused when Duffy was held responsible by Finance Minister, Brian Lenihan, for inciting widespread public fear that Irish citizens were on the verge of losing their savings.

The extent of The Finance Minister's concern first publicly emerged the following morning when he was interviewed by RTÉ's economics editor George Lee.

[15] Journalist Kevin Myers wrote in October 2009, "Throw in some mob-oratory from the national broadcaster's disgraceful 'Liveline', and almost no state institution and no politician is safe from the vengeful, idiot wrath of Madame La Guillotine, or Les Heureuses Tricoteuses.

[18] Duffy defended his own high wages and those of his fellow RTÉ presenters while appearing on TV3's Midweek in October 2011, claiming they were agreed “fair and square”.

[23] In 2018–19, Duffy played (in pre-recorded sequences) the Magic Mirror in the Cheerios Panto, Snow White, making use of some of the Liveline catchphrases, such as "Talk to Joe".

It portrays him as a fetish garment clad sado-masochist who derives perverse pleasure by urging his call-in radio listeners in a strong working class Dublin accent, to express excesses of degradation and misery as he "empathises" verbally and plays with his nipple clamps.

In August 2022, Joe described on his radio programme his terrifying recent encounter with a weever on a Dublin beach, leading to 'excruciating pain' which necessitates him wearing swim boots at all times.