i don't think its a specific rule but falls under a few.but cops the now need lots of evidence like they can see the drugs etc. but i think it should be if we get enough personal statements from people saying its true, i think we should be allowed to as we currently have to detective role to help with this situation of raid people. Also cops raid sometimes under the basis of mouth to mouth and not alot of evidence but it does pay off. so this is a small suggest to what you think.