The freight rail operator Aurizon is suing five environmental activist with the group the group Frontline Action on Coal Incorporated (Flac Inc) over a series of recent protests that stopped coal trains.

"Instead of pursuing peaceful protesters, Aurizon should be assessing their own business model, which is clearly failing to adapt in response to the climate emergency we are facing," said Flac Inc's spokeswoman Hayley Sestokas.

In the case due in the Queensland supreme court on Thursday, Aurizon is seeking $375,000 "user-rent" from the organisation as damages for five separate protests in December and January that blocked the rail line.  The rail operator is in legally-mandated negotiations with Adani, which wants to access the Queensland freight network to link to the planned Carmichael coalmine.

"Aurizon does recognise that everyone has a right to express their opinion but not when it is done illegally and comes at the expense of safety," said a spokesman.  "Unfortunately, high-risk protests on the rail corridor have continued and increased in recent months.  We are concerned it only may be a matter of time before someone gets seriously injured or killed."

Flac Inc spokeswoman Hayley Sestokas doesn't buy that, and believes that Aurizon had "the capacity to lead the way" in addressing climate change.

"Instead, this $8.3 Billion company is attempting to silence dissent by targeting our small volunteer organisation," she told The Guardian.  "Aurizon and Adani have got it very wrong if they think legal attacks will get them off the hook for ignoring scientific consensus and the majority of Australians."