Depending on details, it may not be an unreasonable request. The question is more one of trust: do we trust the FBI that it's a reasonable request?
This is why all the stuff like the activities the Snowden leaks demonstrated or Trump's idiotic harassment of the press through the DOJ are so harmful far beyond the direct harm they did: they justifiable and seriously erode trust, and then there is a serious case like this and "trust us" no longer carries any value. A sad state of affairs where everyone loses.
That said...https://www.cbsnews.com/news/luka-magnotta-wanted-for-canada...
What? Absolutely no one said or even implied any such thing.
Photos of in child sex abuse cases are routinely scrutinized in great detail to reveal clues about the location, time, and anything else that might lead to the individuals in the case.
Interpol has an entire website dedicated to help identify objects in pictures[1], asking members of the public to help identify everyday things like T-shirts. Actually, one of the top results pictures right now is "do you recognise this newspaper?"
No one is suggesting that "wearing this t-shirt" or "having this newspaper" is incriminating in and of itself. Finding these people from vague online pictures where they intend to remain anonymous is tricky business, and sometimes with a bunch of these clues combined with some other information they can identify offenders and/or victims.
Of course there are trade-offs involved in all of this, and it's important we have robust public conversations discussing those; as I mentioned in my previous comment, the lack of trust here is a big issue. But much of this entire thread is ... disappointing. I wish people would keep cooler heads (as well as, you know, actually read the article before commenting).