Liam Payne admits he's worried about Zayn Malik
The 19-year-old, who recently split from long-term girlfriend Danielle Peazer, thinks Zayn is strongly affected by the negative attention he gets on Twitter.
Liam told The Sun: "The only person I really worry about is Zayn, because I don’t think he’s quite accustomed to all of this.
"He’s had a terrible time on Twitter, as did Danielle."
Zayn recently quit the social networking site because of the nasty comments he'd been getting when he logged on.
His last ever post read: "The reason i don't tweet as much as i use to, is because I'm sick of all the useless opinions and hate that i get daily goodbye twitter .
"My fans that have something nice to say can tweet me on the one direction account , x."
The 19-year-old eventually reactivated his account after a campaign from his followers.
And it's not only Liam's best mate Zayn who's been upset by Twitter trolls - his ex Danielle was also a victim.
During her two-year relationship with Liam, she was sent death threats and labelled "ugly".
Now she's single, Danielle will more than likely be free from the insults, but Liam knows Zayn needs to toughen up.
He continued: “I don’t think Zayn’s quite adjusted to it yet, I’m sure he’ll get it. He’s my best mate. I’ve got to look out for him."