Who can see what on Twitter

One of the most confusing thing on Twitter is working out who can see what. I'm going to try to unravel it a bit for you. First of all, to save a bit of waffle, I'll define tweets three ways,

1. a general tweet is how I'll refer to any tweet you send that is either aimed at the world of Twitter in general, or to a specific person but not starting with their username.
2. an @ tweet  is meant for just one person and starts with their twitter name. If you put anything at all before the @, it works like a general tweet instead.
3. a RT is a tweet from somebody else that you have tweeted using Twitter's retweet button. If you have retweeted manually, by copying and pasting the message and starting with RT @  or by quoting it, as some mobile apps do, it works like a general tweet instead.

Now, on to who can see what.

Your Tweets (if your account is not protected)

1. Your general tweets are seen by everyone who follows you, and anyone who looks at your Twitter page, whether they are following you or not. If you have mentioned somebody with an @ in the tweet, it will appear in their mentions whether they follow you or not.
2. Your @ tweets are seen by anyone mentioned by you in the tweet, whether they follow you or not. They are also seen by anyone following both you and the person you mentioned.
3. Your RTs are seen by your followers and the person who made the original tweet.

Note that your tweets ate NOT seen by people who do not follow you, unless either you  @ mention them in the tweet, or somebody they DO follow RTs your tweet, or they visit your own Twitter page.
Anyone who visits your Twitter page will  see ALL your tweets and RTs, whoever they were intended for.

If somebody wants to follow you but doesn't want to see RTs from you - very common amongst non-comping friends of compers- they should go to your Twitter page and use the drop down menu next to the "Following" button to select "Turn off retweets".


Your tweets (if your account is protected)

If your account is protected, your tweets are ONLY seen by people following you.  Even if you send a tweet to somebody by mentioning them with an @, they won't see it if they don't follow you. And if you RT somebody who doesn't follow you, the original tweeter will never know you did it. This is why protected accounts are no use for compers.

When somebody visits your Twitter page, they won't be able to see anything you have said. Even if they follow you, they will need to be logged in to Twitter to see anything. Your followers won't even be able retweet the things you tweet, so absolutely nobody but your followers will ever see a thing you tweet.

People you have blocked

If you block somebody, Twitter automatically unfollows you for them, so your tweets no longer appear in their timeline.  However, if they go to your Twitter page when they are logged out of Twitter, they can see every single thing you have tweeted. Even while logged in to Twitter, they can send you tweets. And if you are having a conversation with somebody, they can retweet the messages mentioning you. So if person A had blocked B. mutual friend C could RT B's tweets for A to see. If somebody they follow who has not blocked them retweets you, the person you have blocked will see that too. Blocking is really more to stop YOU from seeing THEM than THEM from seeing YOU.

Oddly enough, if somebody that you have blocked sends you an @ message, you may still see it, depending on what app you use to view Twitter. And if one of your friends RTs somebody you have blocked, you may still see that too, again depending on how you view Twitter.  It shouldn't happen, but you can't guarantee that it won't!

I've referred in the past to blocking somebody on Twitter as being like sitting in the same room as somebody who you don't want to see or hear, but putting your fingers in your ears and closing your eyes and just carrying on with the conversation while pretending they are not there. While writing this, I was helped by @FussFreeHelen  and it's just confirmed that idea for me - not only that, but if the person you are ignoring  shouts loudly enough you might still hear them!