A video calling to bring a notorious Ugandan warlord to justice has gone massively viral online, but serious concerns have also been raised about the group responsible for posting it.

The so-called Kony2012 initiative, launched by the non-profit group Invisible Children, demands the removal of Ugandan guerrilla leader Joseph Rao Kony. As head of the Lord's Resistance Army, engaged in a complex and continuing conflict, Kony has terrorised villagers in at least four central African countries for nearly two decades.

He stands accused of overseeing the systematic kidnapping of countless African children; brainwashing the boys into fighting for him, turning the girls into sex slaves and killing those who don't comply. His forces are believed to have slaughtered tens of thousands of people and are known for hacking the lips off their victims. Kony has been wanted by the International Criminal Court since 2005 on charges that include crimes against humanity. He has been living in the bush outside of Uganda since that time.

The US designated the LRA a terrorist group after September 11, and in 2008 began actively supporting the Ugandan military. In October the president deployed 100 combat-equipped troops – mostly Special Operations Forces – to Uganda to advise regional military units in capturing or killing Kony.

Yesterday, Invisible Children posted a half-hour video aimed at making sure that mission is accomplished. The organisation argues that by making Kony "famous" pressure will be kept on US policymakers to ensure he is removed.

The video has already received well-over 7m views and the hashtag #StopKony – as well as the words "Uganda" and "Invisible Children" – have been added to Twitter's top 10 worldwide trends. Numerous celebrities have publicly expressed their support for the cause.

Still, some have raised concerns about the organisation behind Kony2012 and the implications of its efforts.

The Tumblr page, Visible Children has collected a number of these critiques. The non-profit's financial statements show that only 32% of the $8.6m it spent last year went to direct services. Meanwhile Foreign Affairs magazine has accused the organization of "manipulat[ing] facts for strategic purposes." Charity Navigator has given Invisible Children a two-star rating in accountability out of a possible four.

Critics point out that the campaign calls on the public to pressure the US to continue working with the Ugandan military, an organisation that has its own record of abuses.

"The Ugandan army continues to commit politically motivated abuses in Uganda," Maria Burnett, senior researcher with Human Rights Watch, Africa Division, told the Guardian.

"We have documented numerous cases in which they've been involved in torture and arbitrary arrests, as well as a score of killings of unarmed protesters and bystanders during political demonstrations in the past three years."

The nature of the US's relationship to Uganda is also potentially problematic, according to Burnett.

"The US, as far as we know, is trying to advise on how to apprehend, or remove from the battlefield, Kony and his leadership," said Burnett.

"I have some concerns about what the US longer term plans are and what kind of exit strategy they may or may not have, but working to apprehend LRA leaders and protect civilians is crucial."