Being harassed for leaving the country

When I lived in San Diego, I would take day trips to Tijuana. and when I came back everybody was in this huge line at the border to get into the country and I just thought that it was such a waste of time that discouraged commerce and disrupted people's lives. Once, upon returning, I was accosted by a customs officer and he threatened to take me to a back room to do things the 'hard way' unless I told him the real reason I went to Mexico (which i informed him was for tacos and beer, which it was).The whole thing was harassing people for leaving the country or for entering the country. It was stupid.