Social invisibility

Unrecognized people
Invisible people
Nonrecognition of people
Forced anonymity
Social anonymity

Social invisibility refers to a group of people in the society who have been separated or systematically ignored by the majority of the public. As a result, those who are marginalized feel neglected or being invisible in the society. It can include elderly homes, child orphanages, homeless people or anyone who experiences a sense of being ignored or separated from society as a whole.

Source: Wikipedia

So called guest workers are often treated as if they do not exist or have any feelings.
(D) Detailed problems