One security firm that tries to maintain a low-profile during its operations is the Greyside Group. However things don't always go to plan. A group of five of its employees were recently arrested in Mozambique for unauthorized possession of weaponry. The small security detail had no documentation for the weapons when they arrived at the airport in Nampula, Mozambique (aaaahhhh the paperwork or was it the lack of a bribe?). It seems that the security detail was hired by the German shipping company NSB to assist in the search (and recovery?) of a hijacked NSB vessel. There are a number of firms that provide maritime security for shipping that have conducted similar operations. Read more in an article entitled "American Security Team Arrested in Nampula By Mozambique Police", The Maritime Executive, September 22, 2011. You can learn more about the Greyside Group at their website www.protectyourships.com.
Ah. Don't trust the initial reports. Evidently Greyside Group says the report is inaccurate and there were no weapons involved. See the links below: