1853 1st Ser. 7 86/1 Straw bail is, I believe, a term still used by attorneys to distinguish insufficient bail from ‘justifiable’ or sufficient bail.
1859 J. R. Bartlett (ed. 2) 455 Straw bail, worthless bail; bail given by ‘men of straw’, i.e. persons who pretend to the possession of property, but have none.