Whats the problem:
A enforced disappearance occurs when force is used (by, for example, agents of a state) to cause a person to vanish from public view, followed by a refusal to acknowledge the deprivation of liberty (and/or by concealment of the fate or whereabouts of the disappeared person), thereby placing the victim outside the protection of law. (Forced Disapperence.)
Why it's a problem: 
Thousands upon thousands of people have been "Removed" from society, never to see their families or freinds again, left for dead or even tortured. When a disappearance happens that person is subjected to whatever the whim of the abducter is, removing all human rights from that person. Generally government officials are involved in Involuntary disappearances, making the victims utterly defenceless to whats happening to them. Because of the threats on peoples lives, and their families, people cant really speak up against there country or anything really if something is wrong, and their voice will not be heard by anyone but possibly family, which even alone can be caught. The punishment for even speaking of disliking a countries way of doing things, an opinion of any sorts almost, can be torture or most of the time, death. With these terrorist like acts, brought down up a countries people by the country officials itself, almost nothing can be done or said about any problems the country has that it itself may have a different view on. (Document - Russian Federation: What justice for Chechnya's disappeared?.)
Why is this happening? 
Many many things can cause a enforced disappearance. A public opinion against the government, or certain plans, conflicting views with government officials, many many things but all mostly based on a persons views. A big target of enforced disappearances is protesters, even so far as large scale organizations members, removing them from civilization and doing as they please to silence them. The government officials use this "Terror" to keep any opposers of any kind silenced, so whatever that persons views or opinions were that might threaten the government or office, they aren't spread to others through any way at all. (Document - Russian Federation: What justice for Chechnya's disappeared?. )
Human Rights Being Violated:
The right to live, and the right to an effective remedy are violated by this crime along with many others depending on what is done to the victim, which varies from case to case. Depending on the reason for the person(s) being contained, more rights can be taken away untill all of them are. (Document - Russian Federation: What justice for Chechnya's disappeared?. )
The complete list of rights, would be ;
- The right to security and dignity of person
- The right not to be subjected to torture or other cruel, inhuman or degrading treatment or punishment
- The right to humane conditions of detention
- The right to a legal personality
- Right to a fair trial
- Right to a family life
- When the disappeared person is killed, the right to life (Enforced disappearances.)
It Happens Everywhere; 
Even in large countries such as Russia, disappearances occur in the thousands. Over a study of Chechnya, within Russia, not a single person within a city (15,000 people per 2km) did NOT know a person who disappeared. Large scale military raids on towns are a often occurence around the world. Armored vehicles and personel come and take whole families away even, taking away anyone they want, without restrictions. ( Document - Russian Federation: What justice for Chechnya's disappeared?. )
In former yugoslavia alone, over 15,000 people have been reported missing, the numbers even greater that have Not been reported. (United Nations: Economic and Social Council)
For example, Bulat Chilaev and Aslan Israilov are believed to have been subjected to enforced disappearance by Russian federal forces. About 10 eyewitnesses saw them being bundled into a car by armed masked men in uniform at a main crossroads in Chechnya on 9 April 2006. Their whereabouts since that time are unknown. A military identity tag was later found near the crossroads and was identified as belonging to a member of the Zapad(West) battalion, a military intelligence unit under the Russian Federation Ministry of Defence. This individual claimed he had lost the tag and denied involvement in the arbitrary detention, and allegedly has since been killed. No one has yet been identified as a suspect in the investigation into the two men’s enforced disappearance (Document - Russian Federation: What justice for Chechnya's disappeared?.).
Where do they end up? 
Most cases of enforced disappearences are never concluded and the bodies never found, alive or dead. Most cases where they are found, the victims are dead and their bodies left in Mass Graves. Forensic evidence usually concludes torture and abuse to the victims body before death, bound and gagged, untill theyre finally killed. Very rarely is a person ever returned from a disappearance and even if then they are closely watched, possibly to be taken again, for good. (Document - Russian Federation: What justice for Chechnya's disappeared?. )
What IS being done: 
Cases are being brought up against the countries themselves for failure to observe these raids, and work to return those lost to them. Many times have occured where countries are brought to court, though many many cases are dismissed without any kind of compensation for their lost loved ones. The court usually does not have enough evidence, nor can anyone usually identify the captors or anyone they saw if they even saw anyone take them away. Merely denying the accusations against them, the officials can get away easily either way, whether they did it or not. (Document - Russian Federation: What justice for Chechnya's disappeared?. ) Some organizations though, are getting the word out about enforced disappearances still such as Amnesty International, in the following quote' "Every year Amnesty International also joins activists around the world to observe 30 August as the International Day of the Disappeared, to remember those who have disappeared and their relatives" (Enforced disappearances.)
Forced Disapperence. (n.d.) In Wikipedia. Retrieved from http://en.wikipedia.org/wiki/Forced_disappearance
Amnesty International. Document - Russian Federation: What justice for Chechnya's disappeared?. Retrieved from http://www.amnesty.org/en/library/asset/EUR46/026/2007/en/12164a2a-d383-11dd-a329-2f46302a8cc6/eur460262007en.html
Amnesty International. Enforced disappearances. Retrieved from http://www.amnesty.org/en/enforced-disappearances
United Nations: Economic and Social Council. Report on the visit to former Yugoslavia by a member of the
Working Group on Enforced or Involuntary Disappearances at
the request of the Special Rapporteur on the situation of
human rights in the former Yugoslavia.
Retrieved from http://www.unhchr.ch/Huridocda/Huridoca.nsf/TestFrame/153891a321ef3ac78025672b0044acfa?Opendocument