Which states prohibit paramilitary activity or 'going armed to the terror of the public,' and what penalties do those laws impose?

1. The baseline: all 50 states prohibit private paramilitary conduct, but not in one uniform law

Multiple legal surveys and guidance documents assert that state and federal law do not authorize private armies and that “paramilitary activity is unlawful in all 50 states,” a conclusion emphasized in Georgetown ICAP’s guidance and fact sheets ^{[1] [2]}, yet these prohibitions appear in different statutory forms—state constitutional subordination clauses, criminal statutes forbidding drills or parades, statutes banning paramilitary training, and laws against impersonating police—so the operational scope depends on which statutory category exists in a given state ^{[6] [7]}.

2. How state laws typically break down: drills, training, impersonation, and public terror

Legal analyses group state anti‑paramilitary rules into distinct types: criminal bans on drilling or parading with firearms (about 28 states by one count), statutes outlawing group training in weapons or explosives in furtherance of civil disturbance (reported in roughly 25 states), and prohibitions on falsely assuming law‑enforcement functions or parading as a militia—each targets a different behavior, from public displays to organized training that could enable violence ^{[3] [4] [6]}.

3. Penalties vary: prison and fines in some states, civil injunctions in others

Penalties are heterogenous: some states impose traditional criminal punishments—prison terms and fines—while newer or revised laws create civil tools for prosecutors and victims to seek injunctions and damages. Idaho’s statute historically allowed up to ten years in prison and/or a $50,000 fine for training people “to maim or kill” to further civil disorder, illustrating how severe criminal sanctions can be in certain jurisdictions ^[8]. By contrast, Oregon’s recent bipartisan statute emphasizes civil enforcement: it authorizes the state attorney general to obtain court orders enjoining paramilitary activity that threatens public safety and permits lawsuits by victims of vigilante conduct ^[5].

4. Gaps in enforcement and the push for clearer federal and state frameworks

Despite legal coverage in every state, commentators and lawmakers stress that many statutes are outdated, underenforced, or unevenly known to local officials, creating a gap between law on the books and public safety outcomes; this enforcement gap is the impetus behind recent state legislative efforts in Oregon, New Mexico, Vermont, and elsewhere to clarify and strengthen prohibitions and by federal lawmakers proposing the Preventing Private Paramilitary Activity Act (PPPA) to create uniform civil and criminal remedies at the national level ^{[9] [10] [5] [11]}.

5. Precedent and practical enforcement: civil injunctions and federal prosecutions

Court and enforcement practice shows multiple pathways to stop paramilitary groups: courts have used state anti‑militia laws and public‑nuisance doctrines to enjoin violent groups historically (for example, a 1982 Texas federal injunction against the Texas Emergency Reserve/KKK), civil injunctions have been effective where criminal prosecutions are politically or practically difficult, and federal charging options (conspiracy, terrorism statutes, restricted‑grounds offenses) can produce harsher penalties when crimes cross federal lines—yet application depends on facts, jurisdiction, and prosecutorial choices, underscoring why advocates press for clearer, modernized statutory schemes ^{[12] [13] [14]}.

All sourced materials describe the mosaic: the universal bottom line is legal prohibition in all 50 states, but what conduct is targeted and what punishment follows varies—ranging from civil injunctions and statutory fines to multi‑year prison sentences—while enforcement and statutory clarity remain uneven and the subject of active reform efforts at both state and federal levels ^{[1] [4] [5] [8]}.