- first, before anything, long chat and let them tell you stheir entire eve story
- ask them who they are, what they do, why they play, who they know in game and so on. everyone is different, but every little bit of inconsistency should be checked - also too consistent as well
- use ESI and other sources to check their story, get an overall image of them, look if it makes sense, ask if something doesn’t add up
- for instance: plays 1 year all the time, should have some experience in EVE. plays 1 year only 1 hour on weekends, will not know much about the game. relatively new player knows too well about very old game changes… hm. could be well-informed. does he make impression to be generally well-informed or not? if not, it’s inconsistent.
- Financial history. (wallet/journal)
- also: asking where do they get their ISK from. if they say real money for PLEX let them show you the bill (lel)
- Skills. (if Skills are too “clean”, it’s not a main; if Skills don’t fit story etc.)
- using eve-search or something to check if char has been sold in the past
- Screenshot from login screen might be an option now, but it could be faked, so need to think about a way to make it work
- if ESI can do this: overall login time, overall stats on activities such as ratting and mining and flying around
- Zkillboard, evewho and so on; with who did they fly, in which area did they often appear etc.
- also eve-search or looking here for Forum posts that might tell you about them. if they wrote heavily against PVP here, but they pretend they always liked it, they’re lying. Liar does not mean they’re spy, but the question is: do you want a liar who could be a spy or just a liar?
- inventory (ESI): is it scattered enough or very clean? does it make sense considering their story?
- screenshot of in-game map using filter for “visited systems” (Personal / Visited Systems) or better with ESI
- personal bookmarks, if ESI can allow this
- location of jump clones
- their online times (regarding timezone etc.)
- their personal contacts (and standigns)
And so on.
I think in general it also helps to think about who could send a spy to your group and what their specific goal could be. It may not help much, but at least it gives more understanding what to look for. Do they have much ressources? Are they known for infiltrating? Are they afraid, do they seek revenge, are you competition or do they want your money or could they want to destroy you? What are reasonable scenarios? What does this tell you about the information they want to collect, the privileges they want to get?
Also think about how they see your group and how you would try to infiltrate your own group. What kind of story would you use, how would you communicate, how would you gain trust and so on. I think emotion is one of the larger dangers. If you like someone immediately or feel sorry for them, you should be more careful with your check and maybe ask a 2nd opinion by a corpmate.
If they get trial, watch their behaviour. Are they in fleet 24/7 but never do anything? Weird. Does their behaviour fit the impression you got considering the new environment for them? Good.
There are many more ways, but in the end I think it is just part of checking if the person fits to your group. The ESI data should be checked, because many people would make some mistake. Good spys will probably not, at least not with this data.
You can never be 100% sure if someone is a spy or not. The thing is, if you mistrust everyone, this can also destroy your group.
I think the best protection is using game mechanics correctly, have levels of trust, making sure that no low-effort spy joins and that new members are included in a lot of activity. After all, a professional spy might want to sit in fleet and get intel, but might not want to participate too much because they’re dual-boxing on their main. And if they’re really good/comitted, this way at least you’ll have them fun playing with them, before they f*ck you over.
Also, creating an atmosphere were loyalty is strong helps I think. If we look at the examples of the PL Clone Bay or The Judge, it seems that due to personal conflicts loyalty got lost and this could turn non-spy into spy. Enforce people showing basic level of respect towards each other.