I concur - a few months ago I used the mobile Web site on an iPhone. I was idly scrolling around the "People You May Know" list while distracted. I noticed that if you merely scrolled the page by swiping and your finger happened to start on top of someone's profile, it would immediately invite that person to connect without any confirmation.

It was a pretty horrifying realisation that I'd become one of those random inviters - now I have much more sympathy to people I've never heard of inviting me to connect! I refuse to use the mobile site again, so I haven't checked if it's been fixed.