You've been warned -- many times, in fact.

Whether you use Facebook, or blog, or tweet, or otherwise use social media to broadcast your whereabouts, you've been warned about the downside of telling a wide swath of people that you're not home right now. "Oh," you say, "they're all my friends."

If you've ever creeped on others' Facebook pages in search of the long-long classmate, or discovered the portals that "friends of friends" can open, you know how easy it is to find way more about a person than they may mean to reveal.

With the traveling and parties associated with the holidays, the warnings have been revived, but the concerns are more than simply railing against FB's narcissism. Even those folks who know not to proclaim their status as "Off to Grandma's for the weekend!" may not think twice about then gleefully posting photos of the whole family unwrapping gifts.

When was the photo posted?

Four minutes ago.

Bingo!

I don't mean to fan the flames of paranoia here. Any decent crook worth his wirecutters weighs the odds of various homes being unoccupied for the odd evening this time of year. But why make a Grinch's life so easy?

Not convinced that you're oversharing? Here are some figures:

Almost 1 in 5 adults use their profile to communicate with people they don't know.

Almost half of adults who have a current social network profile leave privacy settings open.

More than 9 in 10 teens are social media friends with people they don't know well, if at all.

Some tips:

Switch off the "add location to your tweets" function if you're tweeting while on vacation.

Disconnect Foursquare from your Twitter and Facebook accounts, so it doesn't update those sites when you check in. Better yet, don't check in.

Besides making your home more secure, it will also cut down on the number of your friends and followers muttering, "Who cares?"