Edit: Because people assumed I was talking about the no-fly list specifically; I'm not. The terror watch list also winds up being used to cause problems for people.
From: THE PROGRESS AND PITFALLS OF THE TERRORIST WATCH LIST By: COMMITTEE ON HOMELAND SECURITY https://www.govinfo.gov/content/pkg/CHRG-110hhrg48979/html/C...
> Inaccurate watch list information also increases the chances of innocent persons being stopped or detained because of misidentification.
A page by the ACLU goes into some detail. https://www.aclu.org/other/us-government-watchlisting-unfair...
That list, and others, are not innocent "we're just keeping an eye on these people" lists. Their use causes serious harm.