oh definitely we encounter it semi-frequently on some of our sites. Most are screened by ex-army vets now operating in a private capacity as part of the risk-assessment desk study process. Where there is a risk multiple levels of intervention follow. And if you find something - well large areas get evacuated and measures taken.
re who does it - we have definitely had army officers dispose of ex German WWII bombs that were dropped from the Luftwaffe so I don't think it's quite that simple a divide between the specialisms.