If you need to ask, I'd say no. I've had plenty, but it's hardly something to risk until you have been around long enough to be good at vetting and built up a great degree of second-nature security-consciousness. For some nightmare scenarios, read Nik's book. The skank screaming shit on his driveway makes a funnier story than what must have been a fucking awful experience and there are worse possibilities. No point in labouring them, so if you need to ask, the standard advice is, don't.
