There are plenty of reasons for doing an online background check - and not all of them are dodgy. So here's how to do a thorough online background check without spending any cash.
If you don't know your target's name
Let's assume you want to search for someone whose name you don't know. Say you got a random phone call at 4am, or someone has been spamming you with a certain email and IP address combination, or you really want to find out who that jerk is on the forums you frequent, who goes by a particularly unusual handle.
Phone number/email address
While the US, a number of websites offer reverses telephone lookups – the ability to input a phone number and discover the name or the person or business it belongs to – these are rare in the UK. So it's inputting the number into a search engine and trawling the results.
One of the best places to do a reverse phone number lookup - and a reverse email lookup, while we're at it - is Facebook. While you can't look people up by phone numbers (even if they have it listed on their profile), you would be surprised at how many people leave their numbers on their friends' public walls. If you search for a phone number on Facebook and it's been left on someone's wall (or on one of those 'I lost my phone, need numbers' group walls), it will show up in the search results.
As for email, well, you can search for people on Facebook by email address. And even if their email address isn't publicly available on their profile, if it's in any way affiliated with their profile it will show up.
If you know nothing about the person you're trying to look up except for their username or online handle, fear not. So long as the username/handle is reasonably unusual, you'll be able to find a decent amount of information (which you can then use to perform other searches).
Search the 'Deep Web' with Pipl. Pipl is an aggregator that searches the parts of the internet that are often missed by regular search engines such as Google. Pipl allows you to search by name, email address, username or phone number. Pipl then crawls the web and aggregates all search results that contain your terms - so it's more of a one-stop shop for results.
Pipl is excellent for hunting down information about people whose name you do not know (as for people whose name you do know, it mostly just finds what you can find on Google and social networks). The username search is particularly useful, especially because a lot of people use one handle across the web.
Other aggregator sites also exist, such as ZoomInfo, which aggregates job and company information; iSearch and Wink. Unfortunately, aggregator sites can be as much of a pain as they are a convenience, as they often confuse people and spit back a mix of related and unrelated results.
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