You need to do a little research if you want to sound as if you know what you are talking about, or, as a comedian (more than once) said:
“The lesson of that first day in kindergarten was re-taught to me throughout my life: If you think you’re pretty smart, you’re not talking to enough people.” Cameron, Bruce, “The Smartest Guy in an Empty Room,” Funny Times, September 2013, p. 3.
Onward to the All Writs Act:
If you want to read cases that have interpreted the All Writs Act, you’ll need a full text case law database. Legal encyclopedias, available in print and online at most public libraries, will provide excellent summaries and case references.
Here are links to full-text versions of the act:
United States Code (USC): 28 USC 1651
Statutes at Large (session law):
1) In force (Link from Cornell’s 28 USC 1651 source note: June 25, 1948, ch. 646, 62 Stat. 944; May 24, 1949, ch. 139, § 90, 63 Stat. 102.)
2) The Judiciary Act; September 24, 1789: From Yale’s Avalon Project and Wikisource and at the Office of Law Revision Counsel (with a link to the 1789 Statutes at Large) and at the Library of Congress, which will link you to the digital documents in their Memory Project.