Indeed, in some industries it is a requirement that employers run checks to make sure potential employees do not have any criminal convictions. After all you want to get the best people you can fill your position. Obvious types of jobs such as Police, Social workers, Teachers and Care workers are good examples of careers where full background checks would be essential.
Equally important are claims of experience on CVs and unexplained gaps in employment history. Social media is a great way to make preliminary investigations into employment history and gaps in activity, most people these days have a significant online profile. You can use this in order to confirm what applicants have put on their CV. Companies should be aware, however, that there are risks to this. If people are unemployed they usually say they are looking for work on their activity profiles. When it comes to professional networking sites such as LinkedIn you can usually see their work history, where as social networks such as Facebook or Twitter usually carry information about their social activity. It is not illegal to look at someones Facebook page for the purposes of completing a review of a potential employee. Remember they may have access restricted so you may not be able to see their activity.
You would need to be sure that you are looking at the correct person, you could potentially get two people of the same name, especially if their name is common such as Smith or Johnson. this is where a picture of an applicable is ideal for helping to get the correct information.
Employers used to be able to pay for a CRB (criminal records bureau) check but this has been replaced in 2012 with a DBS (Disclosure Barring Service). This has three levels of check, basic, standard or enhanced. The basic check is the one most commonly used and is only a snapshot on that day and does not contain overseas convictions for example.
Another thing that employers need to be careful of is that some convictions can fall under a categorization of 'spent'. This is where certain types of conviction carry a time lapse element, so for example after 3 years they are considered to be off someone record. In this case if you do a search on someone's name and they were in the news four years ago for a drugs offense which is now lapsed. You are not allowed to use that information as part of your profiling.