Put about 15 rounds in a sock and you have a pretty effective club.
Seriously, as already said, something is better than nothing. .25 ACP gets a bad rap from the prevelance of cheap Sat Night Specials that were chambered for it. The problem was more with the guns and the 2" barrels than the round itself. Would it be my choice, no but if its all you have then go for it. Every caliber can be lethal, shot placement is just more critical with lower mass and energy rounds.
"The whole of the Bill (of Rights) is a declaration of the right of the people at large or considered as individuals.... It establishes some rights of the individual as unalienable and which consequently, no majority has a right to deprive them of." (Albert Gallatin of the New York Historical Society, October 7, 1789)
"A free people ought not only to be armed and disciplined, but they should have sufficient arms and ammunition to maintain a status of independence from any who might attempt to abuse them, which would include their own government." - George Washington