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His phone vibrated in his pocket and he took it out.
It was another text message he didn't want. Some advert or other. He didn't bother reading it, but the end of the message stood out.
TO STOP RECEIVING THESE MESSAGES REPLY WITH 'STOP'.
He received twenty or so of these messages every day. Stopping them would be a fantastic idea.
He followed the instruction and sent his message.
Within seconds his phone was vibrating madly. There were more and more texts from various companies. New ones were arriving faster than he could delete them.
His phone rang. It was a number he didn't recognise, but he answered anyway.
"Hello?"
A message was playing. Something about a pension. He hung up. It rang again immediately. It continued to vibrate as text after text arrived. He turned the phone off and slid it back into his pocket.
A homeless man staggered towards him with a can of strong lager in his hand. As he drew level he took a swig from the can and stared at him.
"You'll never stop them," he slurred and staggered off.