40 USC 8121 – Improper appropriation of streets
(a)
(1) prevent the improper appropriation or occupation of any public street, avenue, square, or reservation in the District of Columbia that belongs to the Federal Government;
(2) reclaim the street, avenue, square, or reservation if unlawfully appropriated;
(3) prevent the erection of any permanent building on property reserved to or for the use of the Government, unless plainly authorized by law; and
(4) report to Congress at the beginning of each session on the Secretary’s proceedings in the premises, together with a full statement of all property described in this subsection, and how, and by what authority, the property is occupied or claimed.
(b)