Plainly, one mouse-clicking troublemaker can destroy reputations, move markets and panic populations.

CNN: BELIEVE IT OR NET

Netflix is currently 9.98% owned by infamous corporate troublemaker Carl Icahn and adopted a poison-pill defense to stop him from getting any more.

FORBES: As Netflix Goes Mickey Mouse, Take a Trip Back to the Future

In London the security service, MI5, initially - and wrongly as it turned out - dismissed Abu Hamza as just a noisy troublemaker.

BBC: End of an era as Abu Hamza to be extradited