Anti-war activists have been hit with a temporary injunction, banning them from protesting within 50 metres of a defence firm's premises in Brighton.
Protesters highlighted the firm's role in making arms systems
But the protesters have claimed an "important victory", saying the injunction does not go as far as restrictions requested by EDO MBM.
The company says the Smash EDO group is engaged in a campaign of unlawful harassment against its workers.
The interim injunction was granted on Friday by a High Court judge in London.
It will last until the full trial in EDO MBM's action, which both they and the defendants hope will begin very soon.
Mr Justice Gross ordered the protest ban under the Protection from Harassment Act, which he said primarily deals with the "phenomenon of stalking" but had also been used in cases involving animal rights and GM crops protesters.
He said he could not accept the protesters' argument that limits should be placed on the use of the act.
He granted the injunction after deciding that the defendants seemed willing to use harassment and criminal acts in pursuit of their campaign.
EDO MBM's action was launched by managing director David Jones, who alleges that 156 employees at the Brighton plant, as well as security guards and three sub-contractors, have been subjected to intimidation and insults.
Andrew Beckett, from Smash EDO, described that claim as "absolute nonsense".
"No individuals who work for EDO have been targeted," he said.
The defence systems firm makes weapons parts at its premises in Home Farm Road.
Protesters blockaded the road outside EDO MBM last year
It wanted protests to be restricted to four-and-a-half hours on Thursday afternoons, with a maximum of 10 people and no artificial or amplifying noise, until a full trial.
But Mr Beckett said the temporary injunction imposed by Mr Justice Gross was "an important victory" for Smash EDO because it contained no conditions on the size or timing of any protest.
He added that protesters "still find the use of anti-stalking legislation [in this case] utterly wrong".
EDO claims a "concerted campaign" of unlawful harassment and is taking action against Smash EDO, the Bombs Out of Brighton Campaign and 12 named individuals.
Smash EDO said its members had been "involved in a year-long campaign of peaceful protest".
They argued that an injunction would have a "draconian and totally unjustified impact", and Mr Beckett added they would be continuing to fight for their right to protest.
Their action has included a roadblock and a 24-hour rooftop occupation.