You’ve set your Facebook privacy so any old Joe can’t see your wild Tahiti vacation photos. And you know better than to accept friend requests from people you don’t know (who would then be able to see your wild Tahiti vacation photos). But are you giving the same attention to your LinkedIn profile’s privacy?

LinkedIn is a network of professionals who share information, referrals, and recommendations. Ideally, people in a network know and can vouch for one another. But if you get a request to connect with someone on LinkedIn, don’t assume you know that person; anyone can ask to connect with anyone else. And while it’s good to strategically expand your professional network, remember that your connections can see your resume (with phone number and home address), profile photo, alma mater, fellow network connections, and 20-year job history. They become the Facebook friends who can see your wild Tahiti vacation photos, only the information on LinkedIn is a lot more personally identifying.

Should you accept a LinkedIn invitation from someone you don’t recognize? Consider these categories of mystery requestors:

1. A second- or third-degree contact. This person may be a referral who is examining your professional prowess before contacting you. Ideally, you would get a heads-up from the referrer or a customized connection request explaining how the requestor knows you. But if you’re not sure, check out this person’s profile to see what industry they’re in and if it might be mutually beneficial to yours.
2. A person you don’t know, who customized their connection request. When a stranger customizes a connection request to explain how they know you or why they’d like to connect with you, most likely that person is genuinely interested in becoming part of your network. You might also realize you met this person at a conference or networking event or at a past employer, or maybe this person follows your business page on Facebook. Consider accepting the request and reaching out to learn more.
3. A person you don’t know, who works in a related industry, in your target clientele, or in your geographic area. Without a customized invitation, your only recourse is to information-hunt on this person’s profile. If this person could be a potential colleague, client, or professional resource, you might want to accept their request. But be sure to make immediate personal contact—send a message thanking them for the invitation, noting what you have in common (“I see we’re both in human resources.”), then fishing for more information (“What drew you to my profile?”). You could turn a preliminary connection into a solid networking relationship, or weed out someone who isn’t serious.
4. A person you flat out don’t know. You can’t figure out how this person found you. You have no connections in common, no shared industry or location, and they sent you a generic connection request. This person could be a spammer or worse, an identity thief, so be cautious. Spammers often lack a profile photo or are located in a foreign country. Spammers might also be legitimate LinkedIn users who send random connection requests in the hope of expanding their network. If you suspect spam, it’s best to ignore the request.

Deciding whom to accept into your LinkedIn network is part investigation and part common sense. A single network connection is never worth jeopardizing your personal information. If you have any doubts about a requestor, remember you can always send a quick note to find out how a person knows you and why they want to connect. At the end of the day, common sense is king; if the invitation doesn’t smell right, it’s best to hit “ignore” and protect your LinkedIn profile just like you would any other personal information. Anyone who genuinely wants to get in touch will find another avenue to contact you.