It's certainly the case that we are asserting, in light of the changed circumstances, that the opportunity to build upon works within the public domain is a fundamental First Amendment interest, and that the First Amendment values, vital speech interest at stake of this case, is that the public domain be permitted as a source for cultivating work about our culture without unnecessary legal restriction.
public domain should not have cumbersome restrictions
Public domain should not have cumbersome restrictions refers to legal restrictions which, in context, states that there should not be any interference from when adding to public domain.
( z1 recommend :ARG1 ( z2 have :polarity - :ARG0 ( z3 domain :ARG1-of ( z4 public ) ) :ARG1 ( z5 restrict :mod ( z6 cumbersome ) ) ) )