We have a duty to think a little further about the things we like (or approve of or bookmark or share or even look at for any length of time) on a social media site.
For ourselves it is important to realise that many social media sites are logging what you say you like and using that to deliver other stuff your way. This means that you will get more stuff related to what you have liked. If this is something that you would actually prefer not to be associated with then be more careful.
For others it can become significant to them that you have liked or shared something and if the origin of that post/comment/picture/video is something of a dubious nature then you are promoting – to your friends – things that are probably not very good for them and to which you would probably not want to be part of.
It doesn’t really matter how funny or how sensible that one post seems – think about the wider message of sharing/liking etc.
We all have a moral duty to be careful what we do on the Web. Just because it is online doesn’t mean our responsibilities end.
St Paul once urged Christians to only engage with things are are good and wholesome – I think he made a good point.