It is important for museums to pay attention to the legal aspects of collecting because in short, it can cause problems for them later on. One of these is making sure that the item in question has an accurate provenance. This is important because it records the origin of the object, supports its validity as an original, and gives the museum proof of ownership. This is also important because if a country comes at the museum with the intentions of taking back the object, it will be more difficult because the objects provenance allows the museum to own it.
Legally, museums also need to worry about how an object was originally acquired. For example, if a museum happens across an item that was illegally collected through the black market or through looting this shows that the museum condones this behaviour. Although on the other hand, is it better for them to not take interest in this object at all and loose both the object, its history, and the education that could be gathered from it by not acquiring it? At any rate, if an illegal object is obtained by the museum, it could allow its originating country to lay claim on such an item because they did not acquire it through the proper means. This would cause the museum to lose both money from the original purchase and standing in the general public’s eyes which could later on result in less money donated to the museum.