Am I too mean?

Do you/would you let your family members, relatives or friends to bring your kid(s) out when you or your spouse doesn't tag along? How much do you trust them in taking good care of your kid(s) in the public?

I've encountered the following situations recently:
1) One evening when I reached home after work, maid told me that my sister-in-law has brought Dillon out, driving him back to her in-law's place, alone. Knowing that her car doesn't have a child car seat, I was so worried how she manage to drive safely with Dillon around, plus she is pregnant also. Then my husband called & told her to send Dillon back immediately. When she reached home, I can see that Dillon is sitting in the front passenger seat, without seat belt. Of course I was very furious for her foolish act and I asked my hubby to tell her never ever do this again.

2) On another evening, my father-in-law brought Dillon out. I thought he brought him for a walk nearby because that is what he does everyday & I do appreciate that. After about 15 minutes, I saw them both came back, in my father-in-law's motorbike. Then I asked him if he brought Dillon for a ride and he said yes, it was only a short distance to the grocery shop . Well, it is not the matter of distance but to put Dillon in the front basket of the bike, without a helmet, is already a very dangerous act. I wasn't happy about it and I told it to my father-in-law directly. (Later on my maid told me that this is not the 1st time Dillon has gone for a ride, arghh!!)

I don't know what do they think about me, esp. my father-in-law, he might think that I was rude to tell him that and my sister-in-law might think I was too mean but I couldn't care less. As a mother, I have the responsibilities & every right to do so to protect my kids.