Watch out for repeated calls that demand the owner's name and then hang up—these are classic red flags. The line +1 646‑661‑2726 shows up in multiple reports as a persistent telemarketing source that offers no clear purpose and often pretends to be a company called Synergy. Protect yourself by adding the number to your phone’s block list, registering with the national Do‑Not‑Call registry, and refusing to share any personal or business details. If the calls continue, report the nuisance to the FTC and share the experience with coworkers so the pattern can be recognized early.
The caller ID displayed a peculiar name, 'fos_pro User', which is the strangest I've seen so far.