Linking with LinkedIn

I've joined LinkedIn & had a good look at it. I was alarmed to discover that, unless you actively make your profile private, everything you put on this site can be Googled. I am very wary of placing personal information on the Web & I would have liked to have had it made very clear at joining that this would be the case unless I actively disabled the function.
LinkedIn is obviously a networking tool for professionals, very oriented towards the United States, & not something that I would use myself. I didn't find it particularly easy to navigate but I can see that the networking groups would be useful for librarians working at the level where world exchange of ideas is necessary & useful eg. the groups concerned with developing E-books.
It would seem to me that the audiences for this & Facebook are very different & that LinkedIn is aimed very much at professional to professional contact rather than aiming for a user audience.
My view as we go on with "23 Things" is that the multiplicity of inofrmation exchange points is ultimately self-defeating. Either you keep every single link valid & up to date or you lose users of links which aren't kept current & you then move into the realm of where on earth the time comes from to do all this updating.
Even scribbling this Blog during the busiest weeks of term has been difficult enough for me.
Also, it seems to me (from the little I know) that information provision is moving more & more towards "Apps" on portable devices (eg. I-phones) & that libraries should be moving more towards creating & providing their own "Apps".
Case in point: were there to be bad weather & a need to inform users of altered opening times, posting a message to, for example, a Bodleian "App." rather than to Delicious, LinkedIn, Facebook, YouTube, E-mails, Web-site etc. etc. would seem to be the simplest, most straightforward thing to do.