I do mild background checks on people sometimes. If a guest doesn’t have verifications, or are new or I just get a gut feeling, I may check to see if they’re on facebook or iG or linked in, but like someone said, that doesn’t guarantee anything, just maybe gives a little piece of mind.
As a landlord, I once rented to an alcoholic who then tried to squat in the property. We paid her to leave to avoid legal hassles. She had excellent references and a normal looking online presence. You really just never know with some people. A nefarious guest can be quite stealth.
Note: some states marry traffic and criminal records, so an inexperienced reader can confuse the two. I had this happen for a job that required an extensive background check. It stated that I had a “criminal record” in another state. It was a seatbelt ticket from 1994, when I had been visiting family out of state and we al piled into my sister’s car, but that state couples traffic and other offenses together. The prospective human resources division could not decipher this information as lay people. I got the job, but we had to settle that first, which I found interesting. So a criminal record, especially one gleaned from a public online source, may not be that at all.
Regardless, sorry that bad guest situation happened to you.