I think it's pretty easy to distinguish a rumor from a real fact of the case.
Just because someone writes something on the internet doesn't make it true, no matter how well-meaning they are. It may or may not be true.
We don't have to be like that guy in Spinal Tap and "believe virtually everything we read" or it leads to confusion. That's what being here on Websleuths has taught me, and I think there are valid reasons for the rules we have.
Personally, I think if someone is making a timeline, they should verify everything with the police because that's what will stand up in court. Other sightings should be listed as "unverified," just as the police would do it, because otherwise it's not going to help at all. People who want to go off searching on wild goose chases are welcome to it, but they shouldn't put down people who can't do it, or who prefer to leave this up to the police.
"Sightings" of missing people happen in every case. What distinguishes them from rumors is whether the police have investigated it or not.
Some sightings are ruled out as misidentification. How many blonde women are there on Signal Mtn? Hundreds? Did anyone see her jeep? Did anyone write down a license number? If someone saw her in a store, what was she buying, and if that store wasn't on the mountain, then they should be aware that there are thousands of tall blonde women in Chattanooga and the surrounding area.
Some people might have their days mixed up too - we saw that in the Hailey Dunn case, even though the people making the reports were well-meaning.
In the Madelyn McCann and Kyron Horman cases, there have been some huge misidentifications of children who merely looked like them. Multiple sightings of each child, to the point that some parents felt harrassed by the press and well-meaning people. So to me, it's a slippery slope to think that just because there was a "sighting" somewhere then it has to be that person. Often that is not the case at all.
Sightings should be treated just like the unidentified deceased woman - if it isn't verified, then it isn't her. That seems simple to me.
A comment on a blog or newspaper, while it may turn out to be true in the future, should be taken at first with a grain of salt. Rumors can turn into facts given time, but some rumors turn out to be completely untrue.
What bloggers write is considered opinion, not fact. If anyone here has a blog, they know what I mean. Bloggers have no limits on what they write, and even though they may have sources just like the MSM, and they may have insider knowledge, and eventually they may be proven right. But here on WS, it's treated like a rumor or a comment, not a fact. Why? Because the bottom line has to be "just the facts ma'am."