A statement was read to the crowd from a chef working in a Byron restaurant who had been taken away "in the most brutal way" and has been deported.
It read: "It made me feel like I never had before. My heart was completely broken about everything.
"They destroyed my family. We were a family but they took some piece of me.
Demo: An activist carries a cutout of Paddington Bear
Lucy Young
"I've been crying loads and loads thinking about them. I was like, 'Oh my God, look after them'.
"I can't do anything but pray. It was really horrible."
Byron had earlier pleaded with protesters to respect the safety of customers and staff after activists said they released thousands of insects into the burger chain's Central St Giles and Holborn branches on Friday evening.
The company claims it had carried out right to work checks on migrant staff and says it was “unaware that any of their workers were in possession of counterfeit documents”.
Byron said in a statement: "In response to the recent Home Office investigation, we would like to reiterate the following.
"Byron was unaware that any of our workers were in possession of counterfeit documentation until the Home Office brought it to our attention.
"We carry out rigorous 'right to work' checks, but sophisticated counterfeit documentation was used in order to pass these checks.
"We have cooperated fully and acted upon the Home Office's requests and processes throughout the course of their investigations: it is our legal obligation to do so.
"We have also worked hard to ensure minimal impact on our customers while this operation was underway."
