Is there any truth to the warning to register for the do not call list to stop calls from telemarketers?

That seems to be a random selection of words about some sort of warning and something about the do not call list and telemarketers, but there is no actual question in there. If you are asking if every possible telemarketers adheres to the do not call list, all the time, the answer is no. If you are asking if some do, the answer is yes.