Ask HN: Should you reply STOP to unwanted texts?

Hacker News Discussion ↗

When to Reply STOP vs Ignore

  • Many argue: never reply to unsolicited texts. Any response (including STOP) confirms a live, engaged number that can be resold or targeted more.
  • Others: reply STOP only to texts from organizations you knowingly gave your number to (banks, stores, password-reset services), not to obvious scams.
  • Some report STOP reducing spam from “semi-legit” senders (brands, political campaigns), but not from pure scammers.
  • Several note that with spam using rotating numbers, STOP only affects that one sender/number and is of limited value.

How STOP Is Actually Handled

  • For US short codes and programmatic SMS, carriers and vendors are generally required (by CTIA/TCPA rules) to honor STOP as an opt-out.
  • Disagreement on mechanics:
    • Some claim carriers intercept STOP at network level.
    • Others state STOP is delivered to the sender’s platform, which must comply or risk losing carrier access.
  • Not all platforms honor STOP; some political/VOIP/marginal providers and certain retailers keep sending despite confirmations.
  • Edge cases: “UNSTOP”/“START” sometimes required to re-enable 2FA or shared short codes; past STOP can silently break verification flows.

Security & Privacy Concerns

  • Several warn that simply opening texts or emails can be risky (historical zero-click exploits on iMessage/Outlook).
  • Concern that URL previews, read receipts, and RCS features can leak that a message was viewed.
  • Core advice from this camp: don’t interact at all; delete or block.

Political Spam & List Sharing

  • US political texts are pervasive and often legally exempt from anti-spam rules.
  • Donating once or giving a number to any campaign can result in years of cross-shared harassment across many committees and PACs.
  • Some users now refuse to donate or vote for candidates who spam, or threaten to support opponents to get removed.

Reporting & Countermeasures

  • Common tactics:
    • Use OS/cellular tools: block numbers, “Report Junk,” forward spam to 7726 (US/UK), enable spam filters, silence unknown callers.
    • Report to FTC/FCC and carriers; a few pursue TCPA litigation for statutory damages.
    • Lookup carriers (e.g., freecarrierlookup-type tools) and file abuse reports with underlying SMS platforms.
    • On iOS/Android, use local SMS filters or keyword rules (especially for political/spam domains); opinions differ on effectiveness.

International & Miscellaneous

  • Behavior differs by country and carrier; in some places STOP is not enforced or is routed through ad companies.
  • Many lament that OSes don’t provide stronger, user-configurable SMS spam filtering comparable to email.