Why is there a lock beside my friend's Twitter username?

[HappyKnife]

Whenever I see this person's username on Twitter, there is a small padlock beside it? What does this mean? I can see her tweets and all, but now I'm curious. It's only beside her username on the Twitter timeline. Everyone else who tweeted does not have this...Why oh why?

[Jennifer Mewes]

your friend has protected her tweets, you follow her so you can see her tweets, everyone who doesn't follow her, can't see her tweets,

[Miaaaaa87]

It means it is a private twitter account. Only approved people can see the account.

You can do it here: http://twitter.com/settings/account
Under protect my tweets.

But I find it ridiculous, if you retweet her... Everyone can still see it.

[Durkin]

She has protected her Tweets. It just means that people that don't follow her can't read them. Anyone that followers her can read them as normal.

Hope this helps!