Last month Delta airlines passengers discovered sewing needles in sandwiches on four different flights. This month Air Canada seems to be having the same problem.
Air Canada also uses an outisde catering company to prepare their prepackaged meals, as did Delta and as do many other airlines. Air Canada released a statement similar to Delta's in that they are working with the catering company to aprehend the culprit and discover the cause for this absurd occurance.
We've said it before and we'll say it again, passengers are better off packing their own PB&J for the time being. Safe travels!