Stolen from CNN
An unclassified advisory, sent July 20 from TSA to law enforcement agencies, raised the possibility that recent activity could be "pre-attack security probes."
The advisory details four incidents from the past 11 months in which screeners found unusual objects with items that could mimic bomb components in passengers' checked or carry-on bags.
In one case last September, a couple in Baltimore, Maryland, checked a plastic bag with a block of processed cheese taped to another plastic bag containing a cell phone charger. Earlier this month in San Diego, California, a passenger checked a bag containing two ice packs covered in duct tape. The ice packs had clay in them instead of the normal blue gel.In response to these incidents, the TSA has updated its travel regulations to prohibit passengers from carrying ice packs or cheese on board aircraft.