Don’t be fooled by Twitter’s ‘new’ blockTwitter now tells anyone you’ve blocked that “You are blocked from following @Someone and viewing @Someone’s Tweets” when they try and look at your profile. Here’s how they can get round that so that they can view your tweets.
Most people probably won’t bother, but don’t be fooled into thinking that your tweets are hidden from someone just because you’ve blocked them. They’re not.
1. They can search for your tweets on Twitter.com
On desktop Twitter (Twitter.com) the easiest way is to type your name into the search box and all your tweets will appear. They can search for from:Someone to see all the tweets that you’ve sent, or just Someone to see all the tweets that you’ve sent or that have been sent to you. Even if you’ve blocked them.
If you post to a #hashtag that they’re following then they’ll see your tweet that way too.
2. I can log out - Twitter no longer knows me
Once someone’s logged out of Twitter it no longer knows that they’re “them” so it doesn’t know that “they” can’t see your tweets and will show them everything, including anything they can’t see when they’re logged in, like your tweets.
3. I disguise myself with a different account
If they have a spare account they can use that to view the tweets of someone who’s blocked them. Or they can use something that can handle multiple Twitter accounts, like Tweetdeck.
4. I can use a different browser
This is pretty much the same as “not being logged in” but without the extra effort. If they’re logged in on Browser A they can view your tweets on Browser B. (Or they can open up a private / incognito tab in Browser A).
5. They can use a different app
While official Twitter apps probably won’t show your profile to someone you’ve blocked there are third party apps like Echofon, Osfoora or Janetter that will (even if they’re logged in).