Magnetic monopoles are intriguing hypothetical particles and inevitable predictions of Theories
of Grand Unification. They are produced during phase transitions in the early universe, but
mechanisms like the Schwinger effect in strong magnetic fields could also contribute to the
monopole number density. I will show how from the detection of intergalactic magnetic fields we
can infer additional bounds on the magnetic monopole flux, and how even well-established limits,
such as Parker bounds and limits from terrestrial experiments, strongly depend on the acceleration
in cosmic magnetic fields. I will also discuss the implications of these bounds for minicharged
monopoles and magnetic black holes as dark matter candidates. The discussion on this paper is
based on [1–3] and some preliminary results.