[nradov]

Generally there is nothing illegal about altering a legal document, or even a strict definition of what counts as a legal document. Under some circumstances it could be illegal to alter a document and use that for fraud, or submit an altered document to a court or government agency. If the doctoring falsely defames someone then you could also open yourself up to a civil suit.

[dylan604]

If you can be sued for it, sounds like it's prohibited to me

[cess11]

Perhaps I misunderstand what "sue" includes in US jurisdictions but prohibition in this context ought to be criminalisation, i.e. something that happens in the relation between the individual and the state, and to me 'suing' is something that happens in a relation between individuals.

[nradov]

Nope, that's not how the US legal system works. Anyone can sue for anything. That doesn't mean they'll win.