If you continue reading NEC 334.30 you'll come to subsection (B)...
334.30 Securing and Supporting Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties, straps, hangers, or
similar ﬁttings designed and installed so as not to damage the cable,
at intervals not exceeding 1.4 m (4 1⁄2 ft) and within 300 mm (12 in.)
of every outlet box. junction box, cabinet, or ﬁtting. Flat cables
shall not be stapled on edge. Sections of cable protected from
physical damage by raceway shall not be required to be secured within
(A) Horizontal Runs Through Holes and Notches. In other than
vertical runs, cables installed in accordance with 300.4 shall be
considered to be supported and secured where such support does not
exceed 1.4-m (4 1⁄2-ft) intervals and the nonmetallic-sheathed cable
is securely fastened in place by an approved means within 300 mm (12
in.) of each box, cabinet, conduit body, or other nonmetallicsheathed
FPN: See 314.17(C) for support where nonmetallic boxes are used
(B) Unsupported Cables. Nonmetallic-sheathed cable shall be permitted to be unsupported where the cable:
(1) Is ﬁshed between access points through concealed spaces in ﬁnished
buildings or structures and supporting is impracticable.
(2) Is not more than 1.4 m (4 1 ⁄2 ft) from the last point of cable
support to the point of connection to a luminaire or other piece of
electrical equipment and the cable and point of connection are within
an accessible ceiling
So if the structure is accessible, you must secure the cable. If you are fishing cable, you do not have to secure the cable. No trained mice with staplers required.