Restaurants have written to the Government over a coordinated “campaign of abuse” from those against the use of vaccine certs for indoor dining.
The Restaurant Association of Ireland says its members have been hit with fake reviews and abusive comments.
It also says some of those against vaccine certs book restaurant slots and don’t show up, depriving businesses of revenue.
A number of pub and restaurant owners have highlighted such issues, both before and after Monday's reopening of indoor dining.
One Dublin pub owner earlier this week said he'd received online death threats and abuse after posting his new menu on social media in preparation for reopening.
Anthony Gray, meanwhile, reopened his two restaurants in Sligo for indoor dining earlier this week.
He says there have been "very nasty swipes" directed at people.
He said: "We're only trying to run a business, look after our staff, and look after our families.
"We certainly don't need this abuse - it's another obstacle that's being put in front of us."
Restaurants Association CEO Adrian Cummins says the organisation has now written to the Government about the problem, and is warning that fake bookings and reviews are causing serious damage.
He said: "[Restaurateurs] are trying to rebuild their businesses and their lives.
"Now they're in the frontline of this anti-vax war. We're the collateral damage."
Restaurants have also called on tech companies such as Facebook to act.
However, the social media giant says the comments do not violate the site’s policies.