A food poisoning expert says companies need to do more to prevent contamination as concern over copy cats licking and spitting in food grows

• Viral videos of people licking and spitting in food and drinks, then returning the contaminated goods to grocery stores' shelves, are sparking customer concerns. 
• Food poisoning expert Bill Marler said that most customers shouldn't worry about the gross videos, as dangerous contamination is more likely to happen at other stages in production. 
• However, manufacturers should be worried about backlash against brands that are contaminated in videos, especially with the treat of copy cats pulling similar stunts. 
• "It's a little bit like terrorism," Marler said. "You can do a lot, but you can only do so much." 
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A rash of viral tweets showing people licking or spitting in things like ice cream and Listerine are sparking customer concerns. But, according to a food poisoning expert, manufacturers should be the ones who are scared. 

Police were involved in two incidents in which people posted videos of themselves licking tubs of Blue Bell ice cream, then placing the tubs back in freezers.

Read more: A man was arrested after posting a video of himself licking a tub of ice cream and putting it back on the shelf - even though he ended up buying it

A mother in Jacksonville, Florida reportedly faces felony charges after a video of her daughter licking a tongue depressor went viral. Other viral videos appear to show shoppers spitting in a Listerine container and an Arizona tea jug.

The viral videos have sparked fury online, as customers condemn the contamination. 

"You can get diseases from human saliva," food-poisoning advocate and attorney Bill Marler told Business Insider. "And, it is product tampering." 

Charges of product tampering can result in up to a twenty-year prison sentence and thousands of dollars in fines. Marler says that he doesn't know if jail time is the right solution - especially for the 17-year-old who posted the original video of herself licking a tub of ice cream. 

"They're freaking stupid," Marler said. "I don't know if throwing them in jail is the right thing." 

However, Marler said that copy cats are a concern. While there are few obvious prior examples of people risking felony charges to go viral, Marler notes Instagrammers and other social media users are known for "doing weird things." 

Even with the upswing of viral videos, Marler says there is no reason for most customers to panic. There is a chance of illnesses spreading if the licker has a communicable disease, but customers are more likely to get food poisoning from contamination at earlier stages in the production chain.

For example, in 2015, three people died in a listeria outbreak linked to Blue Bell ice cream. FDA inspectors found several violations in Blue Bell factories that could have contributed to the outbreak. Meanwhile, no illnesses have been linked to any of the viral licking videos as of Wednesday. 

Manufacturers, not shoppers, should be the ones to worry. 

A video of product contamination going viral could seriously impact customers' perception of a brand, even if no one gets sick. Marler says that manufacturers should think seriously about adjusting the packaging to prevent tampering and alert customers if a product has been tampered with. 

Yet, Marler acknowledged that there is a limit to how much companies can do to prevent tampering. Some of the videos currently going viral were filmed months before the current concerns, meaning that any updates to packaging would do little to prevent backlash.

"It's a little bit like terrorism," Marler said. "You can do a lot, but you can only do so much."