def FindDuplicates(seq):
  """Identifies duplicates in a list.

  Does not preserve element order.

  @type seq: sequence
  @param seq: Sequence with source elements
  @rtype: list
  @return: List of duplicate elements from seq

  """
  dup = set()
  seen = set()

  for item in seq:
    if item in seen:
      dup.add(item)
    else:
      seen.add(item)

  return list(dup)