"Parental rights group" [sic]. More like the "It's intolerable for my child to be exposed to a book where a girl's uncle marries a man, even though my child has classmates with LGBTQ+ family members, and somehow that's not intolerable but a book is" group. Let's call them the anti-book group.
Now, does MCPS routinely use fees as a barrier for Public Information Act requests? Yes, they do. That is well known. On the other hand, we don't know what the anti-book group is asking for. If the anti-book group is asking for records where MCPS will have to do a lot of legal review because of the Public Information Act's exceptions to disclosure, then yes, it's perfectly valid for MCPS to charge for a lot of legal review. The Public Information Act provides options for the anti-book group:
1. Appeal the fee to the Public Information Act Compliance Board.
2. Ask the Public Information Act Ombudsperson to mediate.
3. Sue MCPS.
Or they can run to national Fox News. Which doesn't seem like a very effective strategy for a group that is trying to distance itself from the Christian supremacist hate group M4L, but they didn't ask for my advice.