Yes, that's the whole point of tech used by law enforcement: to enable the enforcement of law. If we don't like the law (and I don't), we should change it!

But focusing on the ALPR here is just silly, as a quick glance of this partial list of other technologies used by law enforcement officers in the course of enforcing the law will show: * cars * guns * phones * handcuffs * computers * the internet * notebook and pen

All of these can be used to "enable authoritarianism", and indeed, any authoritarian regime would be hard pressed to run without them. Some of them are more important than others, and ALPRs are definitely a major improvement in the "who is going where" part of law enforcement -- but the problem is the bad law, not the enforcement thereof.

Your argument reduces to "some laws are bad, so we should have weak enforcement mechanisms, because otherwise people will be unable to evade prosecution for breaking bad laws, and that is bad, because the laws are bad and therefore those who break them should not be subject to prosecution." This is not as helpful a move as it might seem, since it just sends us back to the original question, which is "ok, what laws should we have?"

For better or worse, we have a setup in which we have one branch charged with answering that question, and another charged with enforcing whatever laws we happen to have. Trying to undermine one branch in order to compensate for the stupidity of another is unlikely to help.