I didn't try particularly hard at all. It's a pretty obvious consequence of the two. It is already a problem for email, but most people are getting much more s

I didn't try particularly hard at all. It's a pretty obvious consequence of the two. It is already a problem for email, but most people are getting much more savvy with this and are mostly at least aware of the risk. With SMS, it's not so common. So people are less likely to expec it, and (certainly in my experience) they are more trusting of an SMS that looks like it comes from a legit source, especially if it contains personal info about you. This is partly because people are usually more wary of giving out their mobile number - I know that I've given it out to very few places, and most of them are ones that I trust. The O2 issue massively impacts this, as there's thousands of sites who now potentially have my number (and many of those will be linked to some personal info about me). But it's also partly because most people don't realise that you can spoof SMS headers this way - if you get a text message that claims to be from a particular number, most people assume that it came from that number. I'm not making any comment on the cause of it (whether it's a bug or a design feature), or whether there's anyone to "blame" (and if so, who). I'm simply pointing out that there is quite a significant overap between the two, as the combination creates a potential spammers' paradise.