I recently received a Facebook page link, with a weird querystring payload. The payload was in the form:
?\__xts__[0]=68.XXXXXXXXXXX....
where XXX were random characters (looks like base64, but couldn't decode it).
I googled for: "facebook __xts" and there are several results and pages containing similar querystrings. all start with \__xts__[0]=68.
Is it a Facebook SEO bug or malicious links?