I make sure they don't get in. if most people can do it right then they can as well.
annnnd I normally let these people in because half of the time they're not forcing themselves into your lane because they're jerks but because they're panicking over the fact they just realized it's not a turning lane. If they're doing it on purpose then whatever, those kinds of people are the ones who are always getting into accidents. People are weiners; grow some patience and get over your roadrage and let the loser in instead of risking a pointless fender bender. (^^^^^ not directed towards you specifically dotnet)