2FM DJ Rick O'Shea (@rickoshea)
Followers – 24,129.
"I still think a lot of people on Twitter don't get just how careful you have to be about what you say and how you say it. You only have to look at all of the legal cases that are going on right now in the UK and elsewhere to see the dangers. I sometimes forget that when I tweet, I'm talking directly to almost 25,000 people. So I tend to use the same rules I do when I'm broadcasting on the radio.
"What's weird is that you have these very famous footballers, the likes of Ashley Cole, who you would assume get very strict media training, and they still tweet stuff that the must know is going to get them into a lot of trouble. Mad.
Kim Kardashian (@KimKardashian)
Followers – 16.5m
Kardashian has previously talked about "the power of Twitter to bring people together" but found herself in a bit of a mess earlier this week when she tweeted "Praying for everyone in Israel". One massive backlash later, she hastily tweeted "Praying for everyone in Palestine and across the world!"
The reality TV star then issued an apology, saying she wanted "to own up to and explain that earlier today I sent out two tweets about saying prayers for the people in Palestine and Israel and after hearing from my followers, I decided to take down the tweets because I realised that some people were offended and hurt by what I said, and for that I apologise".
Dave Moore – DJ on Dublin radio station 98fm (@Dave98FM)
Followers – 13,389
"The attraction for me is the fact that Twitter is a giant conversation. I love the fact that I can, essentially, continue my radio show outside of the four hours per day I'm actually on the air.
"But it's more than that. Some of the relationships I've built up on Twitter are people I would today call friends. Some of them, I've never even met in real life. Some of them, I hang out with weekly and I only met them through Twitter."