Using other peoples pictures....

It's not OK when the owners of the content say it's not OK and/or you know you stole it and used it without proper permission. Nobody else can read your mind, but you know what your intentions are. You know you're trying to take credit for something that's not yours! That is not OK!!

I think the only real problem would be if the original owner tells you to take it down

i either use pictures from a free-to-use site like pixabay or use my own and add a watermark to identify it as mine. my profile pic came from pixabay, but i embellished it using picmonkey.

You must not use someone else's picture without their permission on a post, because you are making money on the post, and only the copyright owner has the right to do that. Using someone else's picture as your profile pic doesn't seem to do any harm, unless the copyright owner asks you not to, in which case you must take it down immediately. A really good source for free-use pictures is Pixabay--I use those for my posts when I don't have my own photos.

If the person says not to use their picture than it's not okay and if you use a picture of another person that isn't you, so you're catfishing, isn't okay.

Honestly, it is best not to upload pictures which are not yours unless you use the picture of the cat from wikipedia, pixabay, freegdigitalphotos or you had asked the owner for permission. My avatar is the picture of my own cat.

I never use online photos simply because some of them have copyrights. That's ok though because I take all of my own and use them here. Sometimes I will use a screen shot if it's about pet food recalls or something like that.

I think it's bad to use someone else picture and also to pretend be someone else. That's why we need to be careful on internet. My profile pic is a selfie of myself :)