If you block someone on twitter can they still see your tweets?

[Kelsey]

Okay, so long story short, my brother and his girlfriend follow me on twitter, and it bothers me, because Id prefer not to have a family member following me, or someone who tells my family member everything I say.
I don't say inappropriate things, but I have no privacy, as my brother constantly tells my dad everything I say on my twitter.

[easy_peasy]

yes coz you dont need to sign in to read tweets

[Chris G]

Anyone can see your tweets on Twitter.  It is a public message board system.  There is no privacy on Twitter whatsoever.  Bear this in mind when you are posting.  If you want privacy, then use something like Facebook, which is designed to enable you to determine who sees what you post.