I had to vote “see results” because the question is asking for too broad a judgement. Some are, some aren’t. Informants receiving a benefit should be scrutinized but they aren’t necessarily inherently untrustworthy. Things should be determined on an individual basis.

@NicpSUCg you can agree with a statement like "the Danish are well educated" without implying every Dane is well educated

@PhilosophyBear I would tend to agree with your assertion. However, in this case, I believe the variables are simply too numerous to group criminal informants quite so cleanly. The US courts agree with me, by the way. In pattern jury instructions, juries are cautioned to scrutinize such witnesses more stringently and yet are also permitted to give as much weight to such testimony as any other witness, should the jury believe them to be credible. The jury is thus asked to make an individualized judgment on each such witness.