It is controversial.. amongst people who have concerns about private communications and society, from a regulatory and governance perspective.

It's uncontroversial amongst people who value their privacy.

The tension between the two camps (there are obviously nuances and this is a false dichotomy) is at a current peak. It's an ongoing controversy. It's a matter of public debate.

You might have liked it better if the angle had been "...which the government, controversially, wants to clamp down on" or something.