for instance, one can use one's own app: https://www.reuters.com/article/us-usa-election-trump/with-r... “The most important, golden thing in politics is a cellphone number,” said Parscale, who ran Trump’s digital efforts in 2016 before leading the 2020 campaign. “When we receive cellphone numbers, it really allows us to identify them across the databases. Who are they, voting history, everything.”