Hundreds of Congress workers on Wednesday formed a human chain here as part of their party's observance of November 8 as 'black day' on the first anniversary of the demonetisation of high value currency notes.Congress workers dressed in black shirts and pants, led by Delhi unit chief Ajay Maken, raised slogans against the Narendra Modi-led central government at Connaught Place, the heart of the city. The Congress workers carried placards reading "Notebandi ne kiya prahar, thapp ho gaya karobar" (demonetisation hit hard forcing businesses to collapse), "Notebandi ne kiya vivash, 8 November kala diwas" (Demonetisation forced us to observe November 8 as Black day).The Prime Minister had on November 8 last year in a surprise move announced scrapping of Rs 500 and Rs 1,000 notes to curb "black money and corruption".