Some telcos seem quite intent on charging more for bandwidth than the cost of a film in a bargain bin. If telcos continue to strangle bandwidth then physical media will remain viable for a longer period.
It may be that each search term in a full-text index is held in a separate but hidden table and therefore large chunks of text create a large number of rows. This would explain why inserts would be slower and why quotas are more likely to be encountered.
Sending passwords via plain text forms and plain text emails are both bad practices. However, plain text email is distinctly worse because the data can linger for months or years in less secure systems.
A credit card number sent over unencrypted HTTP may only be vulnerable for a brief period. However, a credit card number sent over SSL and forwarded as a plain text email may be vulnerable until the credit card expires.
Is Facebook unaware of Nagle's algorithm? It is trivial to reduce bandwidth by batching notices. You could even set the maximum frequency yourself. Or is this not implemented because it would make the service less addictive and less viral?
JavaScript gives you the most possibilities because you can place semi-transparent items anywhere in a webpage, they can resize with user interaction and move down a webpage as a user scrolls. JavaScript can also be used to re-write a webpage, including changing images, fetching more text, revealing optional form elements and the changing the destination of hyperlinks.
Some, if not all, of this can be achieved with IFrames and Flash but web browser security is such that you'd have to include JavaScript anyhow.
