- SPYON
- Track, as the feds might do to a suspect
- Observe furtively
- Bug out?
- Watch secretly
- Watch like a plant
- Observe through a keyhole
- Watch through a keyhole
- Watch covertly
- Observe surreptitiously
- Watch surreptitiously
- Follow
- Secretly watch
- Watch from the trees, say
- Watch from hiding
- Keep under surveillance
- Watch using bugs
- Watch with a webcam, perhaps
- Surveil secretly
- Investigate, perhaps
- Observe covertly
- Surveil
- Bug
- Watch furtively
- Watch in secret
- Tail, perhaps
- Tail, e.g.
- Watch unseen
- Observe from hiding
- Cover for info
- Secretly observe
- Tail, maybe
- Watch slyly
- Watch through binoculars, say
- Observe secretly
- Shadow, e.g.
- View slyly
- Secretly surveil
- Watch stealthily
- Sneakily surveil
- Secretly monitor
- Wiretap, say
- Bug, say
- Watch from concealment
