G.R. No. 156759 - Macasaet vs. Co, Jr.

Parties and Factual Background
On July 3, 2000, respondent Francisco R. Co, Jr. filed a libel suit (Civil Case No. 00-97907) against Abante Tonite and seven individuals—Allen A. Macasaet (Publisher), Nicolas V. Quijano, Jr. (Managing Director), Isaias Albano (Circulation Manager), Lily Reyes (Reporter), Janet Bay, Jesus R. Galang, and Randy Hagos (Editors)—alleging damages from a June 6, 2000 article.
The case was raffled to RTC Branch 51 in Manila, which issued summons to each defendant at the business address of Monica Publishing Corporation, Intramuros, Manila.

Service of Summons and Substituted Service
On September 18, 2000, Sheriff Raul Medina attempted personal service in the morning and afternoon; both failed because petitioners were “always out” or “roving.”
Concluding further personal attempts within a reasonable time would be futile, the sheriff on September 22, 2000 returned the summons served by substituted service to:

Motions, Orders, and Appeals
On October 3, 2000, petitioners filed a special appearance motion to dismiss for lack of personal jurisdiction and to drop Abante Tonite for lack of juridical personality.
After Sheriff Medina’s testimony confirming two failed personal service attempts and proper substituted service, the RTC denied the motion on March 12, 2001, and also denied reconsideration on June 29, 2001.
Petitioners sought certiorari, prohibition, and mandamus relief from the CA; on March 8, 2002, the CA dismissed the petition and, on January 13, 2003, denied reconsideration.
Petitioners then filed a petition for review on certiorari with the Supreme Court.

Whether the substituted service of summons validly conferred jurisdiction over petitioners.
Whether Abante Tonite, an unincorporated tabloid, may be sued as a party or enjoys corporate personality.