The Hand of Sedna are an Inuit nationalist group functioning out of northern Alaska. The group is highly mobile, moving their headquarters constantly. Thus far, they have sabotaged several spots along the Alaskan Pipeline. They hold bizarre religious beliefs, as do so many cults of Delta Green's experience.
The group's religious tenets hearken back to the ancient Inuit legend of Sedna. Sedna was a woman who was riding in a boat with her father, who wished to kill her. He pushed her out of the boat and, when she held onto the edge of the boat, he drew a knife and cut off Sedna's fingers. The woman sank and drowned, and her severed fingers grew into many of the types of sea mammal. Sedna went on to rule the underwater netherworld of Adlivun.
When Sedna's fingers were cut off, one gave rise to seals, and it was seals coming ashore from which humans evolved, or so say the Hand. The sea is the natural state of humans, and to the sea they must return, for Mother Sedna commands it. It is the goal of the Hand that their sabotage of government installations will make people realize that the sea is man's home.
In addition, the Inuit People's Council (IPC), a legitimate party with representation in the state government, has been partially infiltrated by the Hand. The Hand's infiltration has given rise to the Inuit People's Liberation Front (IPLF), a terroristic organization responsible for many of the attacks on the Pipeline.
A similar organization, presumably a branch of IPLF, exists in the Ungava area in northwestern Quebec. The purported goal of all IPLF branches is, on the surface, the establishment of an independent Inuit homeland. But the initiated members know better.
The current leader of the Hand is believed to be Kyle Mocliuk, and the headquarters is believed to be located currently near the small village of Anaktuvuk Pass, in the Brooks Range. Other branches (Fingers) are spread throughout Alaska.
Addenda: The above description of the Hand was written by Agent XAVIER following his investigation of terrorist attacks on Metro Field in Fairbanks. His opinion is that the Hand, at least the Chatanika Finger, is trying to summon the demonic creature Issitoq, presumably to incur Sedna's wrath.