It has been a factor, certainly. Probably both good and bad. Spolsky was a pioneer in his concepts of "social user interfaces," and that really showed when he did stackoverflow.
Lowering inhibitions is a broad statement. You can get more detailed. Inhibition is multifaceted, lots of flavours. We can be less inhibited about sending a quick "I love you," less inhibited about arguing, being mean, etc.
Over the last 17 years, all this stuff has experienced a massive multiplier effect. Both the positives and the negatives are multiplied and as culture grows around the technology everything gets more complex.