Changes are you've had at some point had one of these junk texts:
"Free Msg: Our records indicate you may be entitled to £3750 for the accident you had. To apply free reply CLAIM to this message. To opt out text STOP"
I rarely get junk texts, but this one even I got. I think I've had about three or four of them in the last year or so. (I suspect they send these texts to random numbers).
At some point I did contact the Advertising Standards Authority, and I got a polite e-mail back advising me that they had received lots of complaints about these texts, but that it was difficult for them to do anything about them as the sender is usually not identifiable. So, I was pleased to see they've finally found the offender. It's an Indian company called 'Various Data Solutions'. If you got some junk mail you want to get rid off, you may want to post it to '26 York Street, LONDON, W1U 6PZ'. After all, they love unsolicited marketing communications…
As an aside, you should never reply with 'STOP' to junk texts like these. Doing so will only confirm that you've received and read the text, which will encourage the bastards to send you more junk and/or sell you number to other junk companies.