Yune

Yune is a character in Deus Ex: Human Revolution. At first, he appears to be a member of the anti-augmentation group Purity First, but is later revealed to have been a mole for Belltower.

Background
Jensen runs into the hacker at the Milwaukee Junction plant, where he is busy hacking into the systems. Before Jensen can take him alive however, Yune is forced to commit suicide rather than be taken, shooting himself in the head with a pistol.

As Purity First is a fanatical anti-augmentation group, and Yune has some extremely advanced cerebral augmentations, it's determined pretty quickly that the hacker was a mole, planted in Purity First to use the petty terrorists as cover for his real mission of hacking into Sarif Industries. His cerebral augs allowed someone else to remote access him and hack through him, and it is both this hacker and Yune's real masters that Jensen's really after.

However, it turns out Yune's employers are more powerful than Sarif anticipated, as under the orders of one Joseph Manderley, the police investigation and autopsy of Yune is sandbagged and the police are forced to lie to Sarif. Jensen must then infiltrate the police station and recover Yune's neural hub himself, before others can get to it.

Later Jensen finds out that Yune was planted into the group by none other than Belltower, under the direction of the Tyrants. Yune's mission was to successfully infiltrate Purity First, using the terrorists as cover, and get them to take over the Milwaukee Junction plant while another hacker, a man apparently named Windmill, hacked Sarif Industries's systems through him. Yune had also set up a broadcast in Derelict Row Baller territory, letting him access a secure backdoor tunnel right into Sarif Industries.