They're the people who give supermarket shoppers a bad name. They blithely eat grapes in the produce section and dried apricots from the bulk food bins. Any unwrapped and mouth-sized morsels are fair game to these poachers. These are not people who look destitute or in need of a good feed either; rather they have a sense of entitlement and a canny eye for a freebie.
They'll use the excuse that they're innocently tasting the goods as a precursor to purchase but this is a feeble attempt at validation for often it's clear they have no intention of actually buying any of the purloined items. Someone who left a comment on Poll: Eating Grapes at the Market: Sampling or Stealing? summed it up nicely: "I don't see how valid the argument for 'sampling' the grapes is ... [P]eople don't bat an eyelid when they buy meat, fish, dairy, other fruits etc without having a taste beforehand, why do they suddenly give a damn when it comes to grapes? This strikes me as a retroactive rationalisation of something that they know is wrong."
The person who quipped "Carjacking: Stealing or Test-driving?" clearly considers so called sampling sessions to be downright theft. Dictionary.com defines "steal" as "to take (the property of another or others) without permission or right" which certainly seems to cover those who sample at the supermarket.
Yet the practice is clearly rife. A US poll found that: "25 per cent of shoppers admit to having stolen from a grocery store" and "36 per cent said they tend to 'sample' while shopping."
What makes so many people so blasé about supermarket theft? Possibly for some there's a blurring of the lines. We're often encouraged to try certain food (perhaps ice cream, peanut butter or fragrant cooked delicacies) in a supermarket if the supplier is promoting it, and perhaps those with poor powers of reasoning then assume the whole store is an all-you-can-eat buffet.