Q: This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
In the beginning of 1996, several human rights groups brought cases to hold Shell accountable for alleged human rights violations in Nigeria, including summary execution, crimes against humanity, torture, inhumane treatment and arbitrary arrest and detention. In particular, Shell stood accused of collaborating in the execution of Ken Saro-Wiwa and eight other leaders of the Ogoni tribe of southern Nigeria, who were hanged in 1995 by Nigeria's then military rulers. The lawsuits were brought against Royal Dutch Shell and Brian Anderson, the head of its Nigerian operation. In 2009, Shell agreed to pay $15.5m in a legal settlement. Shell has not accepted any liability over the allegations against it.
A:
In 1996, multiple groups filed lawsuits to hold Shell accountable for what?