There are rights to free speech.
There are (or used to be) rights to privacy,
There are rights for protection from unreasonable searches and seizures,
When these rights are threatened, in whatever circumstance, the ACLU has an interest.
If the police violate a person's right to protection from unreasonable search and seizure, then irrespective of the predicate crime, that violation of rights must be addressed. I.e., the police should do a better job.