The Manchester United Supporters Trust (MUST) chose the 10-year anniversary of the Glazers' takeover to launch a fresh attack on the American family.
The Glazers' £790million leveraged buyout of United in 2005 caused uproar among the club's fans and sparked the creation of breakaway club FC United.
Ten years on, MUST is still unhappy about the way the family borrowed against the club to finance their takeover.
"Not investing a single penny might be considered an 'ownership crime' by fans at most clubs but far worse than that they (the Glazers) have actually extracted colossal sums from Manchester United," MUST said in a press release.
"When all interest and charges on their leveraged buyout is added up, plus money they've paid themselves, plus related debt still on the club, they've taken more than £1 BILLION and it's still rising.
"No owner in the history of football in any country, ever, has taken so much money from a club."
Despite the controversy surrounding the Glazers, United have enjoyed success on the pitch under their stewardship.
In the last 10 years they have won the Barclays Premier League five times and in 2008 they lifted the Champions League for the third time in the club's history.
MUST says had it not been for mismanagement from the Glazers, United would have eclipsed Liverpool's British record of winning the competition five times.
"When the Glazers took over in 2005 we already had an exciting young squad including Cristiano Ronaldo and Wayne Rooney," the MUST statement added.
"With continued investment that squad should have gone on to dominate Europe for years but the Glazer era squandered that golden chance and although still successful on the pitch it has to go down, in Europe in particular, as a decade of wasted opportunity.
"United should have knocked Liverpool off their European perch too by surpassing their five European Cups.
"It seems very likely we would have done had it not been for financial austerity imposed by the Glazers' ownership."
MUST said the Glazers had "botched" the appointment of Sir Alex Ferguson's successor and that of chief executive David Gill.
The fans' group did admit its relationship with the club had improved over the last two years, though.
"Despite the huge damage inflicted over the last 10 years things are undoubtedly beginning to look positive again in 2015," MUST said.
"Relations between fans and the senior management team have improved vastly in the last two years with genuine dialogue and regular meetings established.
"The costs of servicing the remaining debt are now down to manageable levels and Manchester United is climbing back to the position of financial superiority it occupied for nine years prior to the Glazers arrival.
"It's just a shame we had to go through all the pain and waste of the last decade simply to allow a family with no connection to Manchester United to enrich themselves at the expense of our club and fans."
Manchester United refused to comment on MUST's statement.
Source : PA
Source: PA