Check on Facebook and Twitter accounts before moving forward to accept. Will only perform a check if people have a profile picture.

No profile setup, if your are not interested in being online by not filling in a profile correctly, why should I waste my time hunting your down?

Both Facebook and Twitter, if you don't have any connection to me, why ask for friendship, always see who is friends with whom before accepting.

Being cautious and checking does not mean the odd one will slip through be vigilant to posts on your timeline, cut the person off by blocking them if they really do not show any interest in what you do, or post offensive content you do not approve of immediately, it is a reflection on you as to what goes onto your timeline.