An effort announced Thursday to help companies catch and stop spam text messages therefore had to start with feeding computers a steady diet of SMS spam. Validating unknown numbers remains so difficult—thanks to all the hops a call can take through multiple phone networks—that some firms have found it’s easier to build systems to approve designated calls or texts from companies willing to pay for that vetting and labeling. … [Read more...] about Here’s how hard it is to spot a fake email address or phone number
