A source close to the shadowy Regional Action Committee of Winemakers, or CRAV, told www.BeverageDaily.com the group was planning several attacks on similar targets to those already hit this year.
These include lorries carrying foreign wines, depots, hard-discount retailers and government buildings - all in France's Languedoc Roussillon region.
The situation presents a potential problem for those importing and transporting foreign wine in the region, which borders with Spain.
CRAV has officially claimed responsibility for the recent attack on the Chais du Sud winery in Sète, near to Montpellier.
There, dozens of masked winemakers armed with baseball bats stormed the winery grounds in broad daylight, smashed open the vats, and sent 730,000 litres of wine gushing into the street.
Three people were lightly injured, although CRAV leaders have expressly told activists not to target humans.
Yet, sources say the group is growing in strength as France's wine crisis puts the financial squeeze on many vintners in Languedoc Roussillon.
There are now thought to be around 500 CRAV members in the areas around Nimes and Montpellier alone, with at least another 200, and probably more, further south towards Narbonne.
The Sète action marked the re-start of CRAV's campaign after a brief summer break, and was last week followed up by 250 protestors peacefully occupying the government's regional agriculture offices in Nimes.
Angry vintners in Bordeaux, meanwhile, were busy bricking up the entrance to local wine trade association CIVB - the inter-professional committee for Bordeaux wine.
The actions have made the French government look like it is in danger of losing control of the situation.
Agriculture minister Dominique Bussereau whizzed down to Nimes on Thursday to try and give wine producers yet more reassurance that the government would do what it could to help them.
The wine crisis, which has seen prices fall by more than 40 per cent in some cases, has already been compared to one of the biggest on record back in 1907. Then, mass protests in Languedoc Roussillon forced the government to send in army troops.
Things are not that bad at the moment, but Jean Huillet, head of the General Assembly of Winemakers, said: "It is exactly the same as 1907, some of these people are desperate." He added the blame lay firmly at the door of the agriculture ministry for not doing more to reform the sector.
Opinion is, however, split on the value of the CRAV's extreme actions.
Many vintners at the recent Sitevi 2005 wine production expo in Montpellier said CRAV only hampered the image of French wine.
Yet, tacit and even open support for CRAV exists. Eliette Montosson, a 68-year-old winemaker and activist back in the 1960s and 70s, said attacks on cheap imports of Spanish wine were justified.
Family wine-maker Benoit Lignières and his friend Michel Tailhades took a philosophical approach at a protest earlier this year in Narbonne. "Obviously violence is not the best way, but unfortunately it seems it has been the only thing that has made the government sit up and listen to us."
French wine industry leaders in Languedoc Roussillon recently launched a battle plan, including: a fixed minimum price of €3 per hectare for Vins de Pays for six months; a proposal to rip up and convert more vineyards; and proposals to change the industry structure and improve marketing efforts.
"We have done everything, but there has been no response from the government," said Huillet, who is also head of a local union in Languedoc.