First, what must be said is that your safety is your responsibility. No one can keep you safe when you are looking for a job - or in any other activity for that matter - better than you can yourself.
Online job search is very similar to answering advertisements from the newspapers. Online nanny services do not pre-screen the families, any more than you are pre-screened. The following are some tips to consider:
Follow President Reagan's philosophy - Trust, but verify. The vast majority of families are completely honest and above board. The majority, not everyone. Ask the family for references, particularly their former childcare provider (nanny or daycare).
Practice safe interviewing. Best practices are to meet the family initially in a public place - a fast food restaurant with a children's play area for example. If you must meet in their private home, make sure a trusted family member or friend has all the details of where you are going and when. Many candidates have a friend accompany them to the interview and wait at a nearby coffee shop while you interview.Don't send money! Don't give out your bank account information! There are scams at job search sites where the employer either asks you for money to buy your plane ticket - say half the fare - or offers to 'wire' you the money to your bank for your ticket. You will be ripped off - we guarantee it!
If you are looking for a live in nanny job - online or through an agency it doesn't matter - always have an escape plan - a way to get home or to friends if you don't feel safe or it just doesn't work out.
Trust your instincts. If there is anything about the job or the family that makes you uneasy, keep looking.
Creative Commons Source: http://www.4nannies.com/info/NANNYFAQ.cfm