The Time to go Massimo group last week prompted the Italian to threaten legal action after installing an advertisement outside the ground demanding he sell the club.
The poster – featuring a list of allegedly broken promises and a picture of Cellino with a cross through his face – was taken down after solicitors Ward Hadaway argued it amounted to harassment.
However, the protesters redoubled their campaign ahead of tonight’s match against Middlesbrough.
They projected a series of messages onto the East Stand setting out why they believe his ownership has failed and claiming fans have no confidence in the Cellino regime.
The £2,600 stunt was paid for by crowdfunding and masterminded by EMF Technology, the company famed for projecting a naked image of television personality Gail Porter onto the Houses of Parliament in 1999.
“We have informed the police and have taken legal advice,” ‘Time to Go Massimo’ spokesman Tom Banks said.
“These images are going to be on the stadium itself and they will not be a permanent fixture.
“The club’s legal people have written to us about the poster, claiming it was harassment and caused distress.
“They might do the same again, we can’t speak for the club, but we’re extremely confident we won’t be doing anything illegal.”
The poster campaign features a cartoon image of Cellino under the heading ‘Time to go Massimo’ with various quotes from the former Cagliari owner underneath.
“Between 6:30pm and 10pm this evening (Monday the 15th of February), against the Southern side-end of the East Stand there has been planned a projection of slides putting forward our messages of why his ownership is not good enough, that a sizeable portion of fans have no confidence in the Cellino regime, and why we are urging him to sell the club,” the group said.
The Time To Go Massimo campaign is funded by fans who have grown disillusioned at the way Cellino has run the club following his takeover from previous owner Gulf Finance House in early 2014.
His tenure at Leeds has been overshadowed by an endless chain of controversies and sacked managers.
Cellino served a Football League ban last year for tax evasion in Italy and is currently appealing against a second disqualification having been found guilty of a similar offence.
He agreed to sell the club to fans’ group Leeds Fans United in October after agreeing a deal in principle, only to renege on the promise and while he has confirmed his intention to sell the club he continues to alienate fans.
Cellino angered supporters in December by imposing “pie tax” at Elland Road, increasing ticket prices in the South Stand by £5 in exchange for food and drink vouchers in a bid to stop fans buying beer outside the ground.
He backed down after mass protest but has caused further outrage by claiming in a televised interview with Italian newspaper L’Unione Sarda that he increased ticket prices as a punishment to fans who had chanted for him to sell the club at recent home matches.
Cellino has since said: “It was just a joke. I never could do anything like that.”
The fans’ group has said it has raised over £4,000 from 228 separate donations since asking supporters to join them and help pay for the stunt, which has cost them £2,600.
It was not just Leeds fans making their voice heard on Monday evening as the owner used his programme notes to make his feelings clear about this match being moved for Sky Sports coverage.
The club were forced to deny reports on Sunday that they were taking action against the Football League in a bid to dismantle the collective selling of television rights and instead sell their own games.
It was also reported that the Middlesbrough clash is only going ahead after the League was forced to take out a legal injunction against Leeds to ensure they honoured the fixture, although the club later dismissed the claims.
This is United’s 12th live game of the season - the last time the cameras turned up at Elland Road for a game against Derby on December 29 they were locked out by Cellino before he relented.
There were no such issues this time around but the owner used his programme notes to express his frustrations.
“Tonight’s game is our latest to be broadcast live on Sky and this has once again highlighted our grievances with the number of fixtures we have had re-arranged this season,” he said.
“However, the fans can rest assured knowing that, although we do not wish to announce everything we are doing, we will continue to fight to protect their right to enjoy coming to games at Elland Road at the rightful and traditional time.
“We can accept a small number of fixtures being moved for television, but this season has been entirely disproportionate for Leeds United in comparison with many of the rest of the league.
“It has had a detrimental effect on the club and that will be clear again this evening with a reduction in the attendance and matchday sales.
“We are aware of many supporters, not only from England but from across the world, who had made plans to attend this game on the originally scheduled date of Saturday afternoon at 3pm.
“Many of those actually came to Leeds this weekend because their flights and hotel were already booked, but they have unfortunately had to return home and will miss tonight’s game due to the date being moved back for television.
“Those fans feel the effect financially and emotionally, but it is difficult for their voices to be heard.
“It is with their interests in mind that we continue to push for change.”