I haven't the faintest idea what you thought I meant, Sirius Black. Perhaps your mind is not best suited to considering the useful applications, after all.

I had in mind surveillance of buildings with part of a team outside and one person taking the riskiest part on the inside. Or spying on meetings or events when only one person can reasonably hide close enough in for a proper view of things without being detected.

That sort of thing.

Sly, indeed!

Honestly.