The major institutional constraint is the issue of copyright.
Literal
Institutionally large shackle [becoming-となる] [nominalizer-の] [topic-は], copyright [possessive-の] problem is.
A cleft structure: ~のは...である identifies the constraint. 枷 (かせ, shackle/fetter) is used figuratively for a restriction — vivid vocabulary for an abstract discussion. ~となる is the formal variant of ~になる. 制度的に uses the ~的 adverbial form to scope the claim to institutional matters.