Wednesday's evacuation of the Wando terminal at the Port of Charleston and partial closure of the Wando and Cooper rivers to boat traffic because of a threat onboard of the container ship Maersk Memphis was the latest in a long string of fears of ships being involved in terrorist or political plots. According to a USCG spokesman a YouTube “conspiracy theorist” made a claim about a threat aboard the ship and authorities were investigating the threat ‘out of an abundance of caution’. In two videos posted to YouTube, a man named George Webb claimed there was a "dirty bomb" aboard the ship, loaded in Pakistan during a recent trip to the Middle East. After scanning of four suspect containers revealed no threat, the terminal and rivers have been re-opened today but the incident has revived fears of a so-called dirty bomb that reached its more than a decade ago after the 9/11 incident and measures introduced since. There have been many cases of arms and explosives being smuggled in containers that have been unearthed but fortunately so far no cases of any form of radioactive or biological weapons having been identified. Despite the obvious threat – which may have its origins in the 1984 novel The Fourth Protocol by Frederick Forsyth – efforts to introduce security scanning of containers have routinely been resisted by ship and cargo interests and in some cases by port operators. The reasons against have ranged from the costs to the time needed to scan containers. US regulations in the SAFE Port Act require scanning of all containers from around 750 foreign ports but this has never been enforced and each two years an exemption limiting scanning to just 4% of inbound boxes has been extended, the last time in 2016. Whether the latest threat will see the Act being more rigorously enforced as the new President’s focus on security may suggest, remains to be seen but if it does then the whole debate over scanning can be expected to reignite once more. Image: Stock Library.