You know, FB "offers" me potential friends. Usually people I have seen through the days, and whose phones were in the proximity of mine.
90% of time there is nothing interesting, but if a photo is too good, or peculiar, I might check on them.
Now, if Lucy had her cell phone with her (and we know she did, from another case), and the parents brought theirs into the unit, might it have happened so that the parents' portraits popped up in bottom of her FB in the evening?
Looking up their FB in this case would nor be so surprising.
In short, FB's own algorithm can't be discounted.
These are very good points. The important thing to consider is how FB worked back in 2015 rather than how it works today. The first alleged crime here was nearly seven and a half years ago and that length of time is glacial in electronic development terms.
I rarely use FB these days but when I do I can tell it's not the same as it was even quite recently. The "people you might know" section is no where near as prominent as it used to be. It used to randomly appear in your feed but it doesn't seem to do that anymore. Also, the people who are suggested to you today tend to be more along the lines of people who are friends of friends. I can't recall the last time when FB gave me a friend suggestion of someone who I'd met and had been in close proximity to. That seems never to happen anymore and I wonder whether it's due to some data protection/human rights issue.
The prosecution has said that she "searched" for these people. Did she, though, or did she just view a profile presented to her? Moreover, back in the day, did viewing a random profile which was presented to you get recorded somewhere as a "search"? Even if she did actually use the search bar to search for a name previous searches remain on the search bar until you remove them. If you go to search for something all the recent searches appear on the drop-down and it's tempting to hit that previous name for a catch up on their life.
I can well imagine that if you're asked years later as to why you searched for a particular person on a particular date you wouldn't remember as you may not have even registered in your own mind that hitting that name on the search bar again was a repeat search. You may well see it as a simple link to page rather than hunting someone out again.
Christmas Day is a day on which, I'd guess, that tens of millions of people would be looking people up they haven't seen in a while and suchlike. Clicking on the search bar and seeing those names from recent searches might result in a great temptation to have another look at someone, especially someone who you know has undergone a recent great trauma and especially at Christmas. In fact, it may lead to a little internal moral dilemma - if you see those names on Christmas day do you click on them or simply ignore them? I can see how someone might be conflicted in that.
The point of all this is that I think we need to know the
specific nature of the FB activity before we can pass judgement on it or come to any conclusion as to its evidential value.