People putting a lot of x's in a text?

As far as I know x's at the end of a text or a message means a kiss.

I read a news article about a woman posting the end of her younger brother's romantic relationship on Twitter.

http://www.dailymail.co.uk/femail/article-3572739/Woman-shares-little-brother-s-brutal-break-texts-girlfriend-end-asking-FRIEND-S-number.html#comments

Both her brother and his ex put a lot of x's at the end of their messages.

Does that mean they want to give each other a lot of kisses? If they don't why do they do it?

If you put x's at the end of a message do you owe at person a real kiss?