Facebook has started awkwardly greeting users in their newsfeeds and it's weirding people out

First Twitter ditches favourites, and now this?

Facebook's overly-friendly greetings have been disturbing users (Stephen Lam/Getty Images)

Something funny must be infecting the water supply in Silicon Valley, because social networks are going crazy at the moment.

First, Twitter takes the bizarre, straw-clutching move of changing its star-shaped 'favourites' into heart-shaped 'likes'.

Now, Facebook has started hassling everyone with weirdly polite messages when they sign in.

Facebook has always tried to speak directly to its users more than other social networks, but these new messages are taking things to the extreme.

The greetings give off a slightly HAL-like vibe, and they're making some users a little uncomfortable.

The messages appear to be time-sensitive, with users seeing "Good morning" messages when they wake up and "good evening" messages at night.

Facebook loves to introduce new features on the fly and withdraw them if the experiment doesn't work out - this willingness for features to fail is part of what keeps the company innovating.

But this latest feature is one of Facebook's more unusual ideas.

There's been a mixed reaction on social media - some people love them, some think they're horrific. Only time will tell whether they stick around or get consigned to the dust heap in a few weeks.