Tweetotaller
Someone who claims to abstain from tweeting; to never have tweeted; or to be a recovering tweetaholic.
"I'm a tweetotaller. I've never used Twitter in my life. And even if I did tweet, I could give up anytime I wanted."
tweetotaler
Someone who has a twitter account and stop writing in it.
@Yumyummin do not write anything on twitter. Perhaps it has become a tweetotaler