diff --git a/examples/use_cases/use_case_41_bad_data.py b/examples/use_cases/use_case_41_bad_data.py
new file mode 100644
index 000000000..3c9300c10
--- /dev/null
+++ b/examples/use_cases/use_case_41_bad_data.py
@@ -0,0 +1,25 @@
+"""
+Use case for changing the bad data array.
+"""
+import matplotlib.pyplot as plt
+import numpy as np
+
+import MulensModel as mm
+
+
+raise raise NotImplementedError(
+    "We don't know how to enable this functionality.")
+
+data = mm.MulensData(file_name="my_data.dat")
+data.plot(show_bad=True)
+
+data.bad[12] = True
+data.plot(show_bad=True)
+
+data.bad[np.where(data.mag < 13.)] = True
+data.plot(show_bad=True)
+
+data.good[data.mag < 12.] = True
+data.plot(show_bad=True)
+
+plt.show()
\ No newline at end of file