A campaign by US activists to capture alleged Ugandan war criminal Joseph Kony has gone viral on the web.
Invisible Children's half-hour film on the use of child soldiers by Kony's Lord's Resistance Army has been viewed nearly 10m times on YouTube.
The group aims to bring Kony to justice at the International Criminal Court, where he is charged with crimes against humanity.
Critics, however, have questioned the methods of the non-profit group.
The hashtags #stopkony and #kony2012 were among top trending topics on Twitter on Wednesday as the campaign took off.
A number of celebrities, including P Diddy and Rihanna, tweeted links to the video.
Kony's forces are accused of atrocities in four African countries: Uganda, the Democratic Republic of Congo, the Central African Republic and South Sudan.
US President Barack Obama in October 2011 announced he was sending 100 special forces soldiers to Uganda to help track down Kony.
However, Invisible Children was accused of spending most of its raised funds on salaries, travel expenses and film-making.
Bloggers also pointed out that NGO watchdog Charity Navigator had given the group only two out of four stars for financial accountability.
And an article in Foreign Affairs which accused Invisible Children and other non-profits of having "manipulated facts for strategic purposes" was circulated on the web.
Invisible Children posted a blog to answer the criticism.
Jedediah Jenkins, of Invisible Children, told the Washington Post thatcriticism of the group was "myopic".