Yes.

Extremists or in general any fraction willing to engage in systematic discrimination, harassment, terrorizing or similar love highly detailed non anonymized census data.

Why?

Because it gives them the perfect layout for which areas to harass (areas likely to yield), which to brutalize (areas unlikely to yield or from especially "hated" people), which to best not touch which (areas with too much influence/money or likely to contain hidden sympathizers), which to systematically take apart through other means like building a highway through them (e.g. "hated" communities to strong/connected to brutalize). etc. etc.

All of this has a lot of history weather it's from right extremists like fascists or left extremists(1).

At which point the question is, if the data you collect is that abuseable. Should you even collect it? Is it even really needed?

(1): Like actual left extremists, the a lot of US sources have the habit to label people as left extremists which by EU standards sometimes aren't even left (but centrist) and very far away from extremism...