is it legal to index public parts of facebook?

[Inda Cloud]

Let's ponder the word public for a moment, shall we? Especially number 3:

adjective
1.
of, pertaining to, or affecting a population or a community as a whole: public funds; a public nuisance.
2.
done, made, acting, etc., for the community as a whole: public prosecution.
3.
open to all persons: a public meeting.
4.
of, pertaining to, or being in the service of a community or nation, especially as a government officer: a public official.
5.
maintained at the public expense and under public control: a public library; a public road.