I’ve seen a copy of Cook’s company-wide memo, and the copy reproduced here is accurate. Maciej Ceglowski — who has been in Hong Kong for weeks — responds:

The first allegation is that “the app was being used maliciously to target individual officers for violence”. This makes no sense at all. The app does not show the locations of individual officers at all. It shows general concentrations of police units, with a significant lag.

As the developer and @charlesmok, a Hong Kong legislator, have pointed out, the app aggregates reports from Telegram, Facebook and other sources. It beggars belief that a campaign to target individual officers would use a world-readable crowdsourcing format like this.

Moreover, what are these incidents where protesters have targeted individual police for a premeditated attack? Can Mr. Cook point to a single example? Can anyone? […]

So not only is there no evidence for this claim, but it goes against the documentary record of 18 weeks of protests, and is not even possible given the technical constraints of the app (which tracks groups of police).

The second, related allegation is that the app helps “victimize individuals and property where no police are present”. Again, does Mr. Cook have any evidence for this claim? The app does not show an absence of police, it shows concentrations of police, tear gas, riot flags etc.